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Tutors Answer Your Questions about Miscellaneous Word Problems (FREE)
Question 170506: x varies directly as the square of s and inversely as t. How does x change when s is doubled? When both s and t are doubled?: x varies directly as the square of s and inversely as t. How does x change when s is doubled? When both s and t are doubled? Answer by Mathtut(511) (Show Source):
You can put this solution on YOUR website!remember when a constant like x in our case varies directly with another variable,s squared in our case it takes on this form  and when a constant like x varies indirectly with t it takes on this form xt=k
: together we have xt/s^2=k or 
:
so we have when s is doubled we have  or  meaning x increases by 4 when s is doubled.
:
when s and t are doubled we have  or 
meaning x doubles when s and t are doubled
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Question 170506: x varies directly as the square of s and inversely as t. How does x change when s is doubled? When both s and t are doubled?: x varies directly as the square of s and inversely as t. How does x change when s is doubled? When both s and t are doubled? Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!x varies directly as the square of s and inversely as t.
x = k[s^2/t]
-----------------------
How does x change when s is doubled?
x = k[(2s)^2/t] = 4k[s^2/t]
doubling s quadruples x
-----------------------
When both s and t are doubled?
x = k[(2s)^2/(2t)]
x = 4ks^2/(2t)
x = 2ks^2/t
doubling s and t doubles x
==============================
Cheers,
Stan H.
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Question 170479: Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 4 hours. How much time would it take for them to mow the lawn together?
(Simplify your answer. Type and integer, proper fraction, or mixed number.)
: Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 4 hours. How much time would it take for them to mow the lawn together?
(Simplify your answer. Type and integer, proper fraction, or mixed number.)
Answer by Mathtut(511) (Show Source):
You can put this solution on YOUR website!so Jack can do 1/7 of the job per hour and Marlyn can do 1/4 of the job per hour
:
1/7(t)+1/4(t)=1(job)----->find common denominator---->28 --.so multiply by 28
:
4t+7t=28
:
11t=28
 or 2 6/11 hours for both to mow the lawn
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Question 170479: Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 4 hours. How much time would it take for them to mow the lawn together?
(Simplify your answer. Type and integer, proper fraction, or mixed number.)
: Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 4 hours. How much time would it take for them to mow the lawn together?
(Simplify your answer. Type and integer, proper fraction, or mixed number.)
Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!Jack usually mows his lawn in 7 hours. Marilyn can mow the same yard in 4 hours. How much time would it take for them to mow the lawn together?
------------------------------------
Jack DATA:
Time = 7 hrs/job ; rate = 1/7 job/hr
----------------------------------------
Marilyn = 4 hrs/job ; rate = 1/4 job/hr
-----------------------------------------
Together DATA:
Time = x hrs/job ; rate = 1/x job/hr
----------------------------------------
EQUATION:
rate + rate = together rate
1/7 + 1/4 = 1/x
11/28 = 1/x
x = 28/11 = 2.545454... hrs
===============================
Cheers,
Stan H.
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Question 170417: BILL CAN BUILD A BOOKCASE IN 6 HOURS, BUT IT TAKES HIS FRIEND, DAVID, ONLY 4 HOURS TO BUILD THE SAME BOOKCASE. HOW LONG WILL IT TAKE THEM TO BUILD THE BOOKCASE IF THEY WORK TOGETHER?
GIVE THE ANSWER IN HOURS AND MINUTES: BILL CAN BUILD A BOOKCASE IN 6 HOURS, BUT IT TAKES HIS FRIEND, DAVID, ONLY 4 HOURS TO BUILD THE SAME BOOKCASE. HOW LONG WILL IT TAKE THEM TO BUILD THE BOOKCASE IF THEY WORK TOGETHER?
GIVE THE ANSWER IN HOURS AND MINUTES Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!BILL CAN BUILD A BOOKCASE IN 6 HOURS, BUT IT TAKES HIS FRIEND, DAVID, ONLY 4 HOURS TO BUILD THE SAME BOOKCASE. HOW LONG WILL IT TAKE THEM TO BUILD THE BOOKCASE IF THEY WORK TOGETHER?
-----------------------------
Bill DATA:
Time = 6hrs/job ; rate = 1/6 job/hr
--------------------------------------
Davis DATA::
Time = 4 hrs/job ; rate = 1/4 job/hr
---------------------------------------
Together DATA:
Time = x hrs/job ; rate = 1/x job/hr
----------------------------------------
EQUATION:
rate + rate = together rate
1/6 + 1/4 = 1/x
(10/24) = 1/x
x = 24/10 = 2.4 hrs
--------
0.4 hrs = 0.4*60 minutes = 24 minutes
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Answer: 2 hrs and 24 minutes (time they need to do the job together)
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Cheers,
Stan H.
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Question 170398: A local elementary school is taking orders for a craf they will make. After calculating the cost of supplies the profit associated with making the craft is represented by P(x)=-x^2+130x-3000, where x represents the number of crafts sold and P represents the profilt. Determine the number of orders that could be acepted in order to make a profit. (Give the entire interval of solutions where a profit would be made): A local elementary school is taking orders for a craf they will make. After calculating the cost of supplies the profit associated with making the craft is represented by P(x)=-x^2+130x-3000, where x represents the number of crafts sold and P represents the profilt. Determine the number of orders that could be acepted in order to make a profit. (Give the entire interval of solutions where a profit would be made) Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!the profit associated with making the craft is represented by P(x)=-x^2+130x-3000, where x represents the number of crafts sold and P represents the profilt. Determine the number of orders that could be acepted in order to make a profit.
------------------
Determine when P is > 0
--------------------------
Solve -x^2+130x -3000 = 0
-(x^2-130x+3000) = 0
(x-30)(x-100) = 0
----------------------
Profit interval: 30 < x < 100
=============================
Cheers,
Stan H.
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Question 170392: Stephanie gave her mother 3 wristbands at the end of the day. During the day, she bought 7 wristbands and gave her little brother 2 wristbands. Stephanie began the day with 11 wristbands. That amount doubled when her father gave her more wristbands. How many wristbands did Stephanie have at the end of the day?
To solve this problem, which piece of information needs to be determined first?: Stephanie gave her mother 3 wristbands at the end of the day. During the day, she bought 7 wristbands and gave her little brother 2 wristbands. Stephanie began the day with 11 wristbands. That amount doubled when her father gave her more wristbands. How many wristbands did Stephanie have at the end of the day?
To solve this problem, which piece of information needs to be determined first? Answer by Mathtut(511) (Show Source):
You can put this solution on YOUR website!you need to double the amount of wristbands she had at the beginning of the day which makes 22, then you add the 7 she bought during the day and subtract out the 2 she gave her brother , and the 3 she gave her mother.....ending with 24 at the end of the day.
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Question 170388: Please help me solve this problem: Two presidential candidates havde a total of 1882 votes. The loser got 970 fewer votes than the winner. How many votes did the winner get?
I think I would take 1882-970= 912votes? that makes no sense though. Is there an easy way to figure this out?: Please help me solve this problem: Two presidential candidates havde a total of 1882 votes. The loser got 970 fewer votes than the winner. How many votes did the winner get?
I think I would take 1882-970= 912votes? that makes no sense though. Is there an easy way to figure this out? Answer by checkley77(3624) (Show Source):
You can put this solution on YOUR website!X+Y=1882
X=Y-970 X BEING THE LOSER.
(Y-970)+Y=1882
2Y=1882+970
2Y=2852
Y=2852/2
Y=1,426 WAS THE NUMBER OF VOTE FOR THE WINNER.
PROOF:
1882-1426=456 FOR THE LOSER.
1426-456=970 IS THE DIFFERENCE.
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Question 170287: What's my telephone number? (_ _ _) _ _ _ - _ _ _ _
Each digit is different.
The Product of the sixth and seventh numbers is the third number.
The fourth, eigth, ninth, and tenth numbers are multiples of 3.
The sum of the fourth and sixth numbers is the same as the sum of the fifth and eigth numbers.
The second, third, sixth, and seventh numbers are powers of 2.
The first, fifth, seventh, and tenth numbers are prime.
: What's my telephone number? (_ _ _) _ _ _ - _ _ _ _
Each digit is different.
The Product of the sixth and seventh numbers is the third number.
The fourth, eigth, ninth, and tenth numbers are multiples of 3.
The sum of the fourth and sixth numbers is the same as the sum of the fifth and eigth numbers.
The second, third, sixth, and seventh numbers are powers of 2.
The first, fifth, seventh, and tenth numbers are prime.
Answer by jim_thompson5910(9368) (Show Source):
You can put this solution on YOUR website!Note: I'm going to let a=first digit, b=second digit, c=third digit etc, until I get to j=tenth digit
So the telephone number looks like this:
(a b c) d e f - g h i j
Now let's do some translations:
"The Product of the sixth and seventh numbers is the third number. "
translates to
f*g=c
--------------------
"The fourth, eigth, ninth, and tenth numbers are multiples of 3"
translates to
d, h, i, j are multiples of 3 (giving us the possible values 0, 3, 6, 9)
Note: 0 is a multiple since 3*0=0
--------------------
"The sum of the fourth and sixth numbers is the same as the sum of the fifth and eigth numbers. "
translates to
d+f = e+h
--------------------
"The second, third, sixth, and seventh numbers are powers of 2."
translates to
b, c, f, g are powers of 2 which gives the possible values: 1, 2, 4, 8
Note: 1 is a power of 2 since
--------------------
"The first, fifth, seventh, and tenth numbers are prime."
translates to
a, e, g, j are prime
List of (single digit) prime numbers: 2, 3, 5, 7
You will need to refer back to this list so it might help to write the list on a separate sheet of paper and cross out any digits that we've used
===============================================================
Note: remember, each digit is different which means that NO repeats are allowed.
Since digit j is both a multiple of 3 AND is prime, this means that the only possible digit for j is 3 (since 3 is both a multiple of 3 AND prime)
So j=3
The same can be done with g. Since g is both a power of 2 AND is prime, the only candidate is 2 (since 2 is both a power of 2 AND is prime)
So g=2
Looking at f*g=c, we know that all three are powers of 2. So this means that f*2=some power of 2
So let's try some values of f
f=1 (CANNOT do since 1*2=2; a repeat would occur where g=c)
f=2 (CANNOT do since 2 is already taken)
f=4 (CAN do since 4*2=8; all three are powers of 2)
f=8 (CANNOT do since 8*2=16; 16 is comprised of 2 digits)
So f=4 and c=8
Since we know that g=2, f=4, and c=8 (and there are ONLY 4 digits that are powers of 2), this means that b=1 (by elimination)
Just to recap, we've taken the digits 3, 2, 4, 8, and 1 so far (5 digits taken already).
--------------------------------------
Now let's move onto the equation
d+f = e+h
We know that f=4, so let's plug that in:
d+4 = e+h
Here's where we have to try some combinations
The possible values for d are 0, 6, and 9 (remember d is a multiple of 3 and the digit 3 is already taken)
The possible values for e are 5 and 7 (e is prime and the digits 2 and 3 are already taken)
The possible values for h are 0, 6, and 9 (remember h is a multiple of 3 and the digit 3 is already taken)
So we could have the following:
d=0 OR d=6 OR d=9
e=5 OR e=7
h=0 OR h=6 OR h=9
So let's add some combinations:
Combination 1:
If d=0, e=5, and h=6 (0 already taken), then
0+4=5+6
4=11 ... which is false (cross this combination out)
Combination 2:
If d=0, e=5, and h=9, then
0+4=5+9
4=14 ... which is false (cross this combination out)
Combination 3:
If d=0, e=7, and h=6 (0 already taken), then
0+4=7+6
4=13 ... which is false (cross this combination out)
Combination 4:
If d=0, e=7, and h=9, then
0+4=7+9
4=16 ... which is false (cross this combination out)
Combination 4:
If d=6, e=5, and h=0 (6 already taken), then
6+4=5+0
10=5 ... which is false (cross this combination out)
Combination 5:
If d=6, e=5, and h=9 (6 already taken), then
6+4=5+6
10=11 ... which is false (cross this combination out)
Combination 6:
If d=6, e=7, and h=0 (6 already taken), then
6+4=7+0
10=7 ... which is false (cross this combination out)
Combination 7:
If d=6, e=7, and h=9 (6 already taken), then
6+4=7+9
10=16 ... which is false (cross this combination out)
Combination 8:
If d=9, e=7, and h=0 (9 already taken), then
9+4=7+0
13=7 ... which is false (cross this combination out)
Combination 9:
If d=9, e=7, and h=6 (9 already taken), then
9+4=7+6
13=13 ... which works
So after trying 8 combinations of numbers, we get
d=9, e=7 and h=6
-----------------------------------------------------------
So to recap, we've taken the digits 3, 2, 4, 1, and 8 (from the first part) and the digits 9, 7, and 6 (from the second part)
Altogether, we know that
j=3, g=2, f=4, b=1, and c=8 (from part 1)
d=9, e=7 and h=6 (from part 2)
------------------------------------------------------
Since d=9, h=6, and j=3, using elimination we get i=0 (note: I'm looking at the "multiples of 3" group)
Finally, since e=7, g=2, and j=3, this means that a=5 (note: I'm looking at the "prime numbers" group)
================================================================
Answer:
So we have the following numbers:
a=5
b=1
c=8
d=9
e=7
f=4
g=2
h=6
i=0
j=3
which means that the telephone number is
(518) 974-2603
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Question 170205: Thanks so much for all the help!!! I have one last one that I think I have some clue about but not sure:
A man is carrying rice on a journey. He passes through three custom stations. At the first he gives up 1/3 of his rice; at the second he is allowed to keep 1/3 of what is left; at the third he gives up 1/4 of what remains. After passing through all three custom stations, he has 6 pounds less than he started with. How much rice did he have when he started?: Thanks so much for all the help!!! I have one last one that I think I have some clue about but not sure:
A man is carrying rice on a journey. He passes through three custom stations. At the first he gives up 1/3 of his rice; at the second he is allowed to keep 1/3 of what is left; at the third he gives up 1/4 of what remains. After passing through all three custom stations, he has 6 pounds less than he started with. How much rice did he have when he started? Answer by jim_thompson5910(9368) (Show Source):
You can put this solution on YOUR website!Let x=amount of rice he starts with and y=amount he has leftover
After First Station
Since "At the first he gives up 1/3 of his rice", this tells us that after the first station, he has  pounds of rice leftover
Note: I've subtracted 1/3 of the amount "x" from "x"
Combine like terms to get  . So he has  pounds of rice leftover after the first station (this makes sense because the guard took 1/3 so the man must have 2/3 leftover).
Note: remember, the "x" is just a number (a number in which we do NOT know). However, to help you get an idea of what is going on, let  (ie let's say that he started at 12 lbs of rice). After the first station, he would have  lbs of rice.
--------------------------------------------
After Second Station
Keep in mind that the man still has  lbs of rice.
Since at "the second he is allowed to keep 1/3 of what is left", this means that they will take 2/3 of what he has left.
So this means that you need to subtract like this
Amount he has left - (2/3)*(Amount he has left )
 Multiply
 Combine the fractions.
So after the second station, he has  lbs of rice left.
--------------------------------------------
After Third Station
Finally, because "at the third he gives up 1/4 of what remains", this tells us that we subtract 1/4 of what he has left like this:
Amount he has left - (1/4)*(Amount he has left )
Which algebraically looks like:
 Multiply
 Combine the fractions.
So after the third station, he has  lbs of rice left.
----------------------------------------------------------
Since "he has 6 pounds less than he started with." this means that he ended up with  lbs. Also, we know that he ended up with  lbs of rice (after passing through the third station)
So this means that the two are equal, so...
 Multiply EVERY term by the LCD 6 to clear the fraction.
 Add  to both sides.
 Subtract  from both sides.
 Combine like terms on the left side.
 Divide both sides by  to isolate  .
 Divide.
=============================================================
Answer:
So the man started with 7.2 lbs of rice and the amounts after each station are:
1st station:  so he had 4.8 lbs after the 1st station
2nd station:  so he had 1.6 lbs after the 2nd station
3rd station:  so he had 1.2 lbs after the 3rd station
Since the difference between 7.2 and 1.2 is  this helps confirm our answer.
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Question 170205: Thanks so much for all the help!!! I have one last one that I think I have some clue about but not sure:
A man is carrying rice on a journey. He passes through three custom stations. At the first he gives up 1/3 of his rice; at the second he is allowed to keep 1/3 of what is left; at the third he gives up 1/4 of what remains. After passing through all three custom stations, he has 6 pounds less than he started with. How much rice did he have when he started?: Thanks so much for all the help!!! I have one last one that I think I have some clue about but not sure:
A man is carrying rice on a journey. He passes through three custom stations. At the first he gives up 1/3 of his rice; at the second he is allowed to keep 1/3 of what is left; at the third he gives up 1/4 of what remains. After passing through all three custom stations, he has 6 pounds less than he started with. How much rice did he have when he started? Answer by scott8148(2758) (Show Source):
You can put this solution on YOUR website!follow how much the man keeps __ let x=starting amount
"At the first, he gives up 1/3 of his rice" __ keeps (2/3)x
"at the second he is allowed to keep 1/3 of what is left" __ keeps 1/3 of (2/3)x __ now has (2/9)x
"at the third, he gives up 1/4 of what remains" __ keeps 3/4 of (2/9)x __ now has (1/6)x
"At the end, he has 6 pounds less than what he started with" __ (1/6)x=x-6
multiplying by 6 __ x=6x-36
adding 36-x __ 36=5x
dividing by 5 __ 7.2=x
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Question 170197: Here's another one. I just can't figure these word problems out!
A man is carrying rice on a journey. He passes through three custom stations. At the first, he gives up 1/3 of his rice; at the second he is allowed to keep 1/3 of what is left; and at the third, he gives up 1/4 of what remains. At the end, he has 6 pounds less than what he started with. How much rice did he have when he started?: Here's another one. I just can't figure these word problems out!
A man is carrying rice on a journey. He passes through three custom stations. At the first, he gives up 1/3 of his rice; at the second he is allowed to keep 1/3 of what is left; and at the third, he gives up 1/4 of what remains. At the end, he has 6 pounds less than what he started with. How much rice did he have when he started? Answer by scott8148(2758) (Show Source):
You can put this solution on YOUR website!follow how much the man keeps __ let x=starting amount
"At the first, he gives up 1/3 of his rice" __ keeps (2/3)x
"at the second he is allowed to keep 1/3 of what is left" __ keeps 1/3 of (2/3)x __ now has (2/9)x
"at the third, he gives up 1/4 of what remains" __ keeps 3/4 of (2/9)x __ now has (1/6)x
"At the end, he has 6 pounds less than what he started with" __ (1/6)x=x-6
multiplying by 6 __ x=6x-36
adding 36-x __ 36=5x
dividing by 5 __ 7.2=x
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Question 170100This question is from textbook elementary and Intermediate algebra concepts and application
: Can someone please help me . thank you very much
Ratio and Proportion
A lawyer bills her clients $200 per hour of service. If a client's case requires 39 hours to complete, use proportion to calculate how much the client will owe the lawyer (excluding tax).
This question is from textbook elementary and Intermediate algebra concepts and application
: Can someone please help me . thank you very much
Ratio and Proportion
A lawyer bills her clients $200 per hour of service. If a client's case requires 39 hours to complete, use proportion to calculate how much the client will owe the lawyer (excluding tax).
Answer by checkley77(3624) (Show Source): |
Question 170108: Three men are attending a math conference together. To save money, they decide to share a room. Upon entering the hotel, the man behind the desk states that the room is $30. Each man reaches into his pocket and pays the man behind the counter $10. The men head up to their room.
An hour later the manager realizes that the man behind the front desk chargered the men too much. The room is at a reduced rate for all ‘conference go-ers’. Instead of $30, the room is actually $25. The manager hands the bellboy five one-dollar bills and tells him to return the $5 to the three men. Well, the bellboy was not an honest boy. He knew that the three men didn’t know that they were receiving money back, so he only returned $3 to the men and pocketed the other $2.
This means that instead of each paying $10, each of the three men paid $9. If you multiply $9 by three, you will get $27. If you add the $2 in the bellboy’s pocket, you get $29.
The men originally paid $30…where is the other dollar???
: Three men are attending a math conference together. To save money, they decide to share a room. Upon entering the hotel, the man behind the desk states that the room is $30. Each man reaches into his pocket and pays the man behind the counter $10. The men head up to their room.
An hour later the manager realizes that the man behind the front desk chargered the men too much. The room is at a reduced rate for all ‘conference go-ers’. Instead of $30, the room is actually $25. The manager hands the bellboy five one-dollar bills and tells him to return the $5 to the three men. Well, the bellboy was not an honest boy. He knew that the three men didn’t know that they were receiving money back, so he only returned $3 to the men and pocketed the other $2.
This means that instead of each paying $10, each of the three men paid $9. If you multiply $9 by three, you will get $27. If you add the $2 in the bellboy’s pocket, you get $29.
The men originally paid $30…where is the other dollar???
Answer by ptaylor(1332) (Show Source):
You can put this solution on YOUR website!
There is no "other dollar"
1. The men originally paid $30----it went into the manager's cash register
2. The manager realized that he charged too much, so he gave the bellboy five dollars to return to the men ($25 in cash register $5 in bellboys's hand)
3. The bellboy gave each man one dollar back and kept 2 dollars for himself ($25 in register, each man has $1 =$28 plus the $2 the bellboy kept=$30)
Another way to look at it is as follows: The statement that the men paid $27 for the room is incorrect---they paid $25 for the room and got fleeced out of $2 by the bellboy ($27-$2=$25 and that jives with whats in the cash register)
Gotta keep track of where the $$$ are, otherwise the fingers may leave the hand.
Hope this helps---ptaylor
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Question 170101This question is from textbook elementary and Intermediate algebra concepts and application
: can someone help me I'm 60 years old and I really don't understand this problem please please help. thank you
: Ratio and Proportion
A new virus is released on the internet; the administrator of a department's Local Area Network ( LAN) is given five minutes by a manager to estimate the impact. The administrator samples 15 of the PCs connected to the LAN, and finds that 9 are infected; use proportion to estimate the number of infected PCs if there are a total of 202 PCs connected to the LAN. This question is from textbook elementary and Intermediate algebra concepts and application
: can someone help me I'm 60 years old and I really don't understand this problem please please help. thank you
: Ratio and Proportion
A new virus is released on the internet; the administrator of a department's Local Area Network ( LAN) is given five minutes by a manager to estimate the impact. The administrator samples 15 of the PCs connected to the LAN, and finds that 9 are infected; use proportion to estimate the number of infected PCs if there are a total of 202 PCs connected to the LAN. Answer by Alan3354(1418) (Show Source):
You can put this solution on YOUR website!This was already solved, I copied it fro Stan H, or stanbon.
------------------------------
Use a proportion:
[9 infected/15 sampled] = [x infected/all the PCs]
(9/15) = (x/202)
x = 202(9/15)
x = 202(3/5)
x = 121.2
Round down to get x = 121 infected PC's out of 202
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Question 170059: THE ELECTRIC CURRENT I, IN AMPERES, IN A CIRCUIT VARIES DIRECTLY AS THE VOLTAGE V. WHEN 12 VOLTS ARE APPLIED, THE CURRENT IS 4 AMPERES. WHAT IS THE CURRENT WHEN 18 VOLTS ARE APLLIED?: THE ELECTRIC CURRENT I, IN AMPERES, IN A CIRCUIT VARIES DIRECTLY AS THE VOLTAGE V. WHEN 12 VOLTS ARE APPLIED, THE CURRENT IS 4 AMPERES. WHAT IS THE CURRENT WHEN 18 VOLTS ARE APLLIED? Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!THE ELECTRIC CURRENT I, IN AMPERES, IN A CIRCUIT VARIES DIRECTLY AS THE VOLTAGE V. WHEN 12 VOLTS ARE APPLIED, THE CURRENT IS 4 AMPERES. WHAT IS THE CURRENT WHEN 18 VOLTS ARE APPLIED?
-----------
I = kV
Find "k":
4 = k*12
k = 4/12 = 1/3
-----------
Equation: I = (1/3)V
If 18 volts are applied you get:
I = (1/3)*18
I = 6 amps.
==============
Cheers,
Stan H.
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Question 169971: A truck carrying 3600 cubic feet of cargo consisting of washing machines and refrigerators was hijacked. The washing machine are worth $300 each and are shipped in 36 cubic-foot cartons. The refrigerators are worth $900 each and are shipped in 45 cubic-foot cartons. If the total value of the cargo is $51,000, then how many of each were there on the truck?: A truck carrying 3600 cubic feet of cargo consisting of washing machines and refrigerators was hijacked. The washing machine are worth $300 each and are shipped in 36 cubic-foot cartons. The refrigerators are worth $900 each and are shipped in 45 cubic-foot cartons. If the total value of the cargo is $51,000, then how many of each were there on the truck? Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!A truck carrying 3600 cubic feet of cargo consisting of washing machines and refrigerators was hijacked. The washing machine are worth $300 each and are shipped in 36 cubic-foot cartons. The refrigerators are worth $900 each and are shipped in 45 cubic-foot cartons. If the total value of the cargo is $51,000, then how many of each were there on the truck?
-----------------
value equation: 300w + 900r = 51000
volume equation: 36w + 45r = 3600
=======================================
Rearrange:
w + 3r = 170
4w + 5r = 400
-------------------
Multiply thru 1st by 4 to get:
4w + 12r = 4*170
4w + 5r = 400
--------------------
Subtract 2nd from 1st to solve from r:
7r = 4*170-400
r = 40 (# of refrigerators)
w = 170-3r = 170-3*40 = 50 (# of washers)
===================================
Cheers,
Stan H.
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Question 169985: 5.1.6. what are all of the trigonomic values given that cot=-3 and sin= square root 10/10: 5.1.6. what are all of the trigonomic values given that cot=-3 and sin= square root 10/10 Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!what are all of the trigonomic values given that cot=-3 and sin= square root 10/10
---------------------
Keep in mind that x^2 + y^2 = r^2
------------
cot=-3 = -3/1
Since cot = x/y, x = -3 and y = 1
Therefore r = sqrt(-3)^2 + 1^2) = sqrt(10)
---------------------
Then:
sin = y/r = 1/sqrt(10) = sqrt(10)/10
cos = x/r = -3/sqrt(10)
tan = y/x = -1/3
csc = r/y = sqrt(10)
sec = r/x = -sqrt(10)/3
cot = -3
=========================
Cheers,
Stan H.
|
Question 169978: 22. verify the identity csc(-x)/sec(-x)=-cot x: 22. verify the identity csc(-x)/sec(-x)=-cot x Answer by jojo14344(879) (Show Source): |
Question 169978: 22. verify the identity csc(-x)/sec(-x)=-cot x: 22. verify the identity csc(-x)/sec(-x)=-cot x Answer by jim_thompson5910(9368) (Show Source):
You can put this solution on YOUR website!Note: I'm ONLY manipulating the left side. I'm showing the right side for comparison
 Start with the given equation
 Use the identities  and  to get the left side in terms of sine and cosine
 Multiply the first fraction by the reciprocal of the second fraction.
 Combine and multiply the fractions.
 Use the identity
 Use the identity
 Reduce
 Use the identity
|
Question 169521: A sample of cyclohexane gas occupies a volume of 250 mL at 75°C and a pressure of 1.40 atm. The mass of the gas is 1.030 g. What is the molar mass of cyclohexane? (VII-2)
_____g/mol: A sample of cyclohexane gas occupies a volume of 250 mL at 75°C and a pressure of 1.40 atm. The mass of the gas is 1.030 g. What is the molar mass of cyclohexane? (VII-2)
_____g/mol Answer by jojo14344(879) (Show Source): |
Question 169972: I am having difficulty solving the following problem. Can someone please assist me in doing so. Thanks!
One number is 6 less than another. The product of the number is 72. Find the numbers.: I am having difficulty solving the following problem. Can someone please assist me in doing so. Thanks!
One number is 6 less than another. The product of the number is 72. Find the numbers. Answer by jim_thompson5910(9368) (Show Source):
You can put this solution on YOUR website!"One number is 6 less than another." translates to
"The product of the number is 72" translates to
 Start with the second equation
 Plug in
 Distribute.
 Subtract 72 from both sides.
Notice we have a quadratic equation in the form of  where  ,  , and
Let's use the quadratic formula to solve for x
 Start with the quadratic formula
 Plug in  ,  , and
 Negate  to get  .
 Square  to get  .
 Multiply  to get
 Rewrite  as
 Add  to  to get
 Multiply  and  to get  .
 Take the square root of  to get  .
 or  Break up the expression.
 or  Combine like terms.
 or  Simplify.
So the answers are  or
This means that the numbers are:
12 and 6
OR...
-6 and -12
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Question 169899: cos^2-sin^2=2cos^2-1 prove that this is true: cos^2-sin^2=2cos^2-1 prove that this is true Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!cos^2-sin^2=2cos^2-1 prove that this is true
----------
Note: sin^2(x) = 1 - cos^2(x)
------------------------------------
Substitute that into the left side to get:
cos^2 -(1-cos^2) = 2cos^2-1
cos^2 -1 + cos^2 = 2cos^2-1
2cos^2 - 1 = 2cos^2 - 1
=============================
Cheers,
Stan H.
|
Question 169901This question is from textbook Algebra and Trigonometry
: I have been working on this math problem and I was wondering if someone could help me? Please and Thank You!! I would deeply appreciate it!!
Rational Algebraic Expression
Simplify
(1-r^3)(1-r)^-3This question is from textbook Algebra and Trigonometry
: I have been working on this math problem and I was wondering if someone could help me? Please and Thank You!! I would deeply appreciate it!!
Rational Algebraic Expression
Simplify
(1-r^3)(1-r)^-3 Answer by stanbon(18984) (Show Source): |
Question 169904This question is from textbook Algebra and Trigonometry
: I have been struggling to figure out this math problem and I was wondering if someone could help me? Please and Thank You!! I would deeply appreciate it!!
Rational Algebraic Expression
Simplify
t^4-1 over t^3+t^2+t+1This question is from textbook Algebra and Trigonometry
: I have been struggling to figure out this math problem and I was wondering if someone could help me? Please and Thank You!! I would deeply appreciate it!!
Rational Algebraic Expression
Simplify
t^4-1 over t^3+t^2+t+1 Answer by Alan3354(1418) (Show Source): |
Question 169517: What is the volume, in liters, at STP occupied by 1.35 moles of each of the following gases?
(a) O3 ___L
(b) O2 ___L
(c) NO2 ___L
(d) C2H6 ___L
: What is the volume, in liters, at STP occupied by 1.35 moles of each of the following gases?
(a) O3 ___L
(b) O2 ___L
(c) NO2 ___L
(d) C2H6 ___L
Answer by jojo14344(879) (Show Source):
You can put this solution on YOUR website!With our working formula ---->  ,
see highlighted "n" equals the number of moles. But the problem states that "each" has 1.35 moles. Having said that, isn't your only solving for "1" Volume? (take note, STP, -- no change in Pressure & Temp.)
Considering too, each gases stated have different Molecular weight, how could they be then have the same number of moles?
.
For the given, we solve for  ?
 , Answer
Thank you,
Jojo
|
Question 169906This question is from textbook Algebra and Trigonometry
: I have been struggling to figure out this math problem and I was wondering if someone could help me? Please and Thank You!! I would deeply appreciate it!!
Rational Algebraic Expression
Simplify
x^4-2x^2y^2+y^4 over x^4-x^3y-xy^3+y^4This question is from textbook Algebra and Trigonometry
: I have been struggling to figure out this math problem and I was wondering if someone could help me? Please and Thank You!! I would deeply appreciate it!!
Rational Algebraic Expression
Simplify
x^4-2x^2y^2+y^4 over x^4-x^3y-xy^3+y^4 Answer by nerdybill(1122) (Show Source): |
Question 169514: What volume would be occupied by 86.8 g of F2 gas at STP? (VII-1)
____L: What volume would be occupied by 86.8 g of F2 gas at STP? (VII-1)
____L Answer by jojo14344(879) (Show Source):
You can put this solution on YOUR website!Working Eqn -----> 
where---> 
*Note: At STP,  is atmospheric Pressure &  is Freezing Point.
Solving for  ?

where, 
Via Periodic Table, Atomic Weight of  = "19."
So, 
Subst. ------>

.
Going back Working Eqn,
 , Answer
.
Thank you,
Jojo
|
Question 169519: What is the pressure, in mm Hg, of 39.0 g of CO2 gas at 31°C, contained in a 350 mL vessel? (VII-1)
_____mm Hg: What is the pressure, in mm Hg, of 39.0 g of CO2 gas at 31°C, contained in a 350 mL vessel? (VII-1)
_____mm Hg Answer by jojo14344(879) (Show Source):
You can put this solution on YOUR website!.
It follows Ideal Gas Law -------->  , Working Eqn
where ---> 
Solving for  :

where, 
In ![CO[2]](/cgi-bin/plot-formula.mpl?expression=CO%5B2%5D&x=0003) , there are "2" atoms of Oxygen and "1" atom of Carbon.
Look on Periodic Table, we see  has Atomic Weight --->  . Therefore, its Molecular Weight is expressed as ![MW[O]=2*16=32](/cgi-bin/plot-formula.mpl?expression=MW%5BO%5D=2%2A16=32&x=0003)
.
For Carbon, look on Periodic Table and the Atomic Weight is ---->  .
It's Molecular Weight is expressed as ![MW[C]=1*12=12](/cgi-bin/plot-formula.mpl?expression=MW%5BC%5D=1%2A12=12&x=0003)
.
Therefore, ![MW=MW[O]+MW[C]=32+12=44](/cgi-bin/plot-formula.mpl?expression=MW=MW%5BO%5D%2BMW%5BC%5D=32%2B12=44&x=0003)
Subst.:

.
Going Back our Working Eqn,
 ----------> mmHg?
 , Answer
.
Thank you,
Jojo
|
Question 169512: 545 g of Ar gas are contained in a 13.3 L pressure vessel at at temperature of 90°C. What is the pressure exerted by the gas? (VII-1)
____atm: 545 g of Ar gas are contained in a 13.3 L pressure vessel at at temperature of 90°C. What is the pressure exerted by the gas? (VII-1)
____atm Answer by jojo14344(879) (Show Source):
You can put this solution on YOUR website!.
This follows the Ideal Gas Law ----->  , Working Eqn
where---> 
Highlighted above is not given, so we have to calculate:
Look thru Table of Elements or Periodic Table and you find Molecular Weight for Argon:
So,
 , Subst. in our Working Eqn:
 ------>
 , Answer
.
Thank you,
Jojo
|
Question 169509: A sample of methane gas has a volume of 465 mL at a temperature of 60.0°C. What is its volume at 125°C? ____mL: A sample of methane gas has a volume of 465 mL at a temperature of 60.0°C. What is its volume at 125°C? ____mL Answer by jojo14344(879) (Show Source): |
Question 169508: A sample of methane gas has a volume of 465 mL at a temperature of 60.0°C. What is its volume at 125°C? : A sample of methane gas has a volume of 465 mL at a temperature of 60.0°C. What is its volume at 125°C? Answer by jojo14344(879) (Show Source):
You can put this solution on YOUR website!By Charles' Law--> it's stated the relation of  and  :
![V[1]/T[1]=V[2]/T[2]](/cgi-bin/plot-formula.mpl?expression=V%5B1%5D%2FT%5B1%5D=V%5B2%5D%2FT%5B2%5D&x=0003)
Given------> ![system(V[1]=465ml,V[2]=V[2],T[1]=60+273.15,T[2]=125+273.15)](/cgi-bin/plot-formula.mpl?expression=system%28V%5B1%5D=465ml%2CV%5B2%5D=V%5B2%5D%2CT%5B1%5D=60%2B273.15%2CT%5B2%5D=125%2B273.15%29&x=0003)
*Note: Celsius need to be converted to Kelvin when dealing with Ideal Gas.
Susbt.
![highlight(V[2]=555.7249ml)](/cgi-bin/plot-formula.mpl?expression=highlight%28V%5B2%5D=555.7249ml%29&x=0003) , Answer
.
Thank you,
Jojo
|
Question 169511: A sample of helium gas has a volume of 4.00 L at a pressure of 0.180atm. What is its pressure if the volume is changed to 9.30 L while the temperature is held constant?
_____atm: A sample of helium gas has a volume of 4.00 L at a pressure of 0.180atm. What is its pressure if the volume is changed to 9.30 L while the temperature is held constant?
_____atm Answer by chiefman(9) (Show Source):
You can put this solution on YOUR website!recalling the standard formula p*v=k
where p=pressure,v=volume and k=constant
we have p1*v1=p2*v2 since temparature is contant we have
p1=0.180atm
v1=4.00L
p2=?
v2=9.30L
making p2 to be the subject of our formula we have

p2=(0.180*4.00)/9.30
p2=0.077
hence the new pressure=0.077atm
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Question 169872: COFFEE AT $3.75 PER POUND IS BLENDED WITH COFEE AT $4.25 A POUND. HOW MUCH OF EACH MUST BE USED TO MAKE 50 POUNDS OF A MIXTURE AT $3.95 A POUND?
I HAVE 3.75X+4.25X=197.50
THAN ADD MY TWO X'S 8.00X=197.5
DIVIDE EACH BY 8.00 AND I GET 24.69 THIS ISNT RIGHT HUH???: COFFEE AT $3.75 PER POUND IS BLENDED WITH COFEE AT $4.25 A POUND. HOW MUCH OF EACH MUST BE USED TO MAKE 50 POUNDS OF A MIXTURE AT $3.95 A POUND?
I HAVE 3.75X+4.25X=197.50
THAN ADD MY TWO X'S 8.00X=197.5
DIVIDE EACH BY 8.00 AND I GET 24.69 THIS ISNT RIGHT HUH??? Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!COFFEE AT $3.75 PER POUND IS BLENDED WITH COFEE AT $4.25 A POUND. HOW MUCH OF EACH MUST BE USED TO MAKE 50 POUNDS OF A MIXTURE AT $3.95 A POUND?
-----------------------
Value Equation: 3.75x + 4.25(50-x) = 3.95*50
375x + 425*50 - 425x = 395*50
-50x = -30*50
x = 30 lbs. (# of lbs of 3.75 coffee in the mixture)
50-x = 20 lbs. (# of lbs of 4.25 coffee in the mixture)
===================================================
Cheers,
Stan H.
|
Question 169871: A MAS HAS 5 MORE ONE-DOLLAR BILLS THAN FIVE DOLLAR-BILLS, AND ONE MORE FIVE-DOLLAR BILL THAN TEN-DOLLAR BILLS. ALTOGETHER HE HAS $139 HOW MANY ONE-DOLLAR BILLS DOES HE HAVE?
I DONT THINK I AM SETTING UP THIS PROBLEM RIGHT.
THANKS : A MAS HAS 5 MORE ONE-DOLLAR BILLS THAN FIVE DOLLAR-BILLS, AND ONE MORE FIVE-DOLLAR BILL THAN TEN-DOLLAR BILLS. ALTOGETHER HE HAS $139 HOW MANY ONE-DOLLAR BILLS DOES HE HAVE?
I DONT THINK I AM SETTING UP THIS PROBLEM RIGHT.
THANKS Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!A MAN HAS 5 MORE ONE-DOLLAR BILLS THAN FIVE DOLLAR-BILLS, AND ONE MORE FIVE-DOLLAR BILL THAN TEN-DOLLAR BILLS. ALTOGETHER HE HAS $139 HOW MANY ONE-DOLLAR BILLS DOES HE HAVE?
--------------------------
Let # of 5 dollar bills be "x".
Then # of 1 dollar bills is "x+5".
And # of 10 dollar bills "x-1".
-----------------------------------
Value Equation:
5x + 1(x+5) + 10(x-1) = 139
5x + x + 5 + 10x - 10 = 139
16x = 144
x = 9 (# of 5 dollars bills)
# of 1 dollar bills = x+5 = 14
# of 10 dollar bills = x-1 = 8
=================================
Cheers,
Stan H.
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Question 169867: Worker efficiency. In a study of worker efficiency at Wong Laboratories it was found that the number of components assembled per hour by the average worker t hours after starting work could be modeled by the formula N(t) = -3t^3 + 23t^2 + 8t.
a) Rewrite the formula by factoring the right-hand side completely.
b) Use the factored version of the formula to find N(3).
Please help me figure out this problem I am so confused thank you.: Worker efficiency. In a study of worker efficiency at Wong Laboratories it was found that the number of components assembled per hour by the average worker t hours after starting work could be modeled by the formula N(t) = -3t^3 + 23t^2 + 8t.
a) Rewrite the formula by factoring the right-hand side completely.
b) Use the factored version of the formula to find N(3).
Please help me figure out this problem I am so confused thank you. Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!N(t) = -3t^3 + 23t^2 + 8t.
a) Rewrite the formula by factoring the right-hand side completely.
N(t) = t(-3t^2 + 23t + 8)
---------------------------------
b) Use the factored version of the formula to find N(3).
N(3) = 3(-3^3^2 + 23*3 + 8)
N(3) = 3(-27 + 69 + 8)
N(3) = 3(50) = 150
=======================
Cheers,
Stan H.
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Question 169865: Decreasing cube. Each of the three dimensions of a cube with sides of length s centimeters is decreased by a whole number of centimeters. The new volume in cubic centimeters is given by V(s) = s^3 -13s^2 +54s - 72.
a) Find V(10).
b) If the new width is s - 6 centimeters, then what are the new length and height?
c) Find the volume when s = 10 by multiplying the length, width, and height.
Can someone please help me with this problem. Thank you: Decreasing cube. Each of the three dimensions of a cube with sides of length s centimeters is decreased by a whole number of centimeters. The new volume in cubic centimeters is given by V(s) = s^3 -13s^2 +54s - 72.
a) Find V(10).
b) If the new width is s - 6 centimeters, then what are the new length and height?
c) Find the volume when s = 10 by multiplying the length, width, and height.
Can someone please help me with this problem. Thank you Answer by Alan3354(1418) (Show Source):
You can put this solution on YOUR website!Decreasing cube. Each of the three dimensions of a cube with sides of length s centimeters is decreased by a whole number of centimeters. The new volume in cubic centimeters is given by V(s) = s^3 -13s^2 +54s - 72.
a) Find V(10).
Sub 10 for s
V(10) = 10^3 - 13*10^2 + 54*10 - 72
V(10) = 1000 - 1300 + 540 - 72
V(10) = 1540 - 1372 = 168 cc
---------------------
b) If the new width is s - 6 centimeters, then what are the new length and height?
The product of L x H = (s^3 -13s^2 +54s - 72)/(s-6) = s^2 - 7s + 12
Since that's integers, that's (s-3)*(s-4). There's no way to know which is L and which is H.
c) Find the volume when s = 10 by multiplying the length, width, and height.
-------------------
?? Wasn't that part a? Maybe it means:
(10-6)*(10-3)*(10-4)
= 4*7*6
= 168 cc
Must be, it matches.
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Question 169866: Demand for pools. Tropical Pools sells an aboveground model for p dollars each.
The monthly revenue for this model is given by the formula R(p) = -0.08p^2 -300p. Revenue is the product of the price p and the demand (quantity sold).
a) Factor out the price on the right-hand side of the formula.
b) Write a formula D(p) for the monthly demand.
c) Find D(3000).
I am not sure how to work this problem out. Can someone please help. Thank you: Demand for pools. Tropical Pools sells an aboveground model for p dollars each.
The monthly revenue for this model is given by the formula R(p) = -0.08p^2 -300p. Revenue is the product of the price p and the demand (quantity sold).
a) Factor out the price on the right-hand side of the formula.
b) Write a formula D(p) for the monthly demand.
c) Find D(3000).
I am not sure how to work this problem out. Can someone please help. Thank you Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!Demand for pools. Tropical Pools sells an aboveground model for p dollars each.
The monthly revenue for this model is given by the formula R(p) = -0.08p^2 -300p. Revenue is the product of the price p and the demand (quantity sold).
a) Factor out the price on the right-hand side of the formula.
R(p) = p(-0.08p-300)
----------------------------------
b) Write a formula D(p) for the monthly demand.
D(p) = -0.08p-300
-----------------------
c) Find D(3000).
D(3000) = -0.08*3000-300 = -540
====================================
Cheers,
Stan H.
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Question 169864: Area of a sail. The area in square meters for a triangular sail is given by A(x) = x^2 + 5x + 6.
a) Find A(5).
b) If the height of the sail is x + 3 meters, then what is
the length of the base of the sail?
Can someone please help me with this problem. Thank you
: Area of a sail. The area in square meters for a triangular sail is given by A(x) = x^2 + 5x + 6.
a) Find A(5).
b) If the height of the sail is x + 3 meters, then what is
the length of the base of the sail?
Can someone please help me with this problem. Thank you
Answer by stanbon(18984) (Show Source):
You can put this solution on YOUR website!Area of a sail. The area in square meters for a triangular sail is given by A(x) = x^2 + 5x + 6.
a) Find A(5).
A(5) = 5^2 + 5*5 + 6 = 56 m^2
--------------------------------------
b) If the height of the sail is x + 3 meters, then what is
the length of the base of the sail?
Area = (1/2)base*height
A = (1/2)b*(x+3)
2A = b(x+3)
base = 2A/(x+3)
==================
Cheers,
Stan H.
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Question 169851: THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have?: THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have? Answer by Edwin McCravy(2086) (Show Source):
You can put this solution on YOUR website!THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have?
There are 8 possible solutions:
19, 22, 25, 28, 31, 34, 37, or 40 coins:
1 quarter makes $0.25 plus 39 dimes, $3.90 makes $4.15 with 40 coins.
3 quarters makes $0.75 plus 34 dimes, $3.40 makes $4.15 with 37 coins.
5 quarters makes $1.25 plus 29 dimes, $2.90 makes $4.15 with 34 coins.
7 quarters makes $1.75 plus 24 dimes, $2.40 makes $4.15 with 31 coins.
9 quarters makes $2.25 plus 19 dimes, $1.90 makes $4.15 with 28 coins.
11 quarters makes $2.75 plus 14 dimes, $1.40 makes $4.15 with 25 coins.
13 quarters makes $3.25 plus 9 dimes, $.90 makes $4.15 with 22 coins.
15 quarters makes $3.75 plus 4 dimes, $.40 makes $4.15 with 19 coins.
Edwin
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Question 169851: THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have?: THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have? Answer by checkley77(3624) (Show Source):
You can put this solution on YOUR website!4.15 in quarters & dimes
Q----D--=4.15
-------------------
15---4--=4.15
13---9--=4.15
11---14-=4.15
9----19-=4.15
7----24-=4.15
5----29-=4.15
3----34-=4.15
1----39-=4.15
PICK THE ANSWER YOU LIKE.
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Question 169851: THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have?: THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have? Answer by Alan3354(1418) (Show Source):
You can put this solution on YOUR website!THe coins Phil has are worth $4.15. If they are just quarters and dimes, how many of each coin does he have?
---------------
He might have 1 quarter and 39 dimes. Or 3 quarters and 34 dimes. Or 15 quarters and 4 dimes. There's no way to know.
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Question 169828: Help please,
The speed of the current in a river is 2mph. Jay travels 20 miles upstream and then 20 miles downstream in a total time of hours. Find the speed of the boat.
Let s be the speed of the boat.
Thanks: Help please,
The speed of the current in a river is 2mph. Jay travels 20 miles upstream and then 20 miles downstream in a total time of hours. Find the speed of the boat.
Let s be the speed of the boat.
Thanks Answer by checkley77(3624) (Show Source):
You can put this solution on YOUR website!BELIEVE YOU LEFT OUT THE HOUR FIGURE????
The speed of the current in a river is 2mph. Jay travels 20 miles upstream and then 20 miles downstream in a total time of 5 1/3 hours. Find the speed of the boat. Let s be the speed of the boat.
D=ST
T=D/S
5.33=20/(S-2)+20/(S+2)
5.33=(20[S+2]+20[S-2])/(S+2)(S-2)
5.33=(20S+40+20S-40)/(S^2-4)
5.33=40S/(S^2-4)
5.33S^2-21.333=40S
5.33S^2-40S-21.333=0
uSING THE QUADRATIC EQUATION  WE GET:
S=(40+-SQRT[-40^2-4*5.33*-21.333])/2*5.333
S=(40+-SQRT[1,600+455])/10.6667
S=(40+-SQRT2,055)/10.6667
S=(40+-SQRT45.333)/10.667
S=(40+45.333)/10.667
S=85.333/10.667
S=8 MPH. ANS FOR THE SPEED OF THE BOAT IN CALM WATERS.
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