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josmiceli answered: 9661 problems
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Quadratic_Equations/353639: The president of a company producing water pumps has gathered data suggesting that the average cost in dollars of producing x units per hour of a new style of pump will be c(x)=x^2-22x+166. Determine the number of pumps per hour to produce to keep the average cost below $75 per pump.
1 solutions

Answer 252745 by josmiceli(9664) About Me  on 2010-10-08 14:01:49 (Show Source):
You can put this solution on YOUR website!
c%28x%29+=+x%5E2+-+22x+%2B+166
The average cost to produce x pumps is c%28x%29
Note that to produce 0 pumps
still costs $166
You want to find x when c%28x%29+%3C+75x
Note that $75 is cost per pump, and 75x is
the cost for x pumps
What about c%28x%29+=+75x?
c%28x%29+=+x%5E2+-+22x+%2B+166
75x+=+x%5E2+-+22x+%2B+166
x%5E2+-+98x+%2B+166+=+0
Solve using quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a+=+1
b+=+-98
c+=+166
I can't finish- Have to run
but that's the start


Travel_Word_Problems/353200: A car and truck leave an intersection at the same time. The car heads ddue north at 55 mph and the truck heads due west at 50 mph. Find their distance apart at the end of four hours. Assume that both the car and truck maintain their speeds for the entire time.
1 solutions

Answer 252379 by josmiceli(9664) About Me  on 2010-10-07 13:07:56 (Show Source):
You can put this solution on YOUR website!
The car and truck each have an equation
For car:
d+=+r%2At
d+=+55%2A4
d+=+220 mi
For truck:
d+=+r%2At
d+=+50%2A4
d+=+200 mi
By the pythagorean theorem:
distance apart = sqrt%28220%5E2+%2B+200%5E2%29
sqrt%2848400+%2B+40000%29
sqrt%2888400%29+=+297.321
They are 297.321 mi apart after 4 hrs


Age_Word_Problems/353094: My house is three times as old as my car. In another three years it will be twice as old as my car.
How old is my car?
1 solutions

Answer 252330 by josmiceli(9664) About Me  on 2010-10-07 09:17:20 (Show Source):
You can put this solution on YOUR website!
Let c = age of car now
Let h = age of house now
given:
h+=+3c
h%2B3+=+2%2A%28c%2B3%29
--------------
By substitution:
3c+%2B+3+=+2c+%2B+6
c+=+3
and
h+=+3c
h+=+9
The house is 9 years old and the car is 3 years old


Graphs/353103: graph the system of linear inequalities x<3;2x+y>7
please show me how you get the points
to graph theres suppose to be a line under the < by the 3 so = to
thank u
1 solutions

Answer 252326 by josmiceli(9664) About Me  on 2010-10-07 09:10:40 (Show Source):
You can put this solution on YOUR website!
x+%3C=+3 is the area to the left of the vertical line at x+=+3 and
also including the line itself.
If you shaded that area, then you would shade the area above
the line x+%2B+y+=+7, and that would be x+%2B+y+%3E7, which is
y+%3E-x+%2B+7
Where those 2 areas intersect is the answer
Graphing:
+graph%28+400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+-x+%2B+7%29+


Travel_Word_Problems/352673: a passenger train leaves a train depot 2 hours after a freight train leaves the same depot. The freight train is traveling 20 mph slower than the passenger train. Find the rate of train if the passenger train overtakes the freight train in 3 hours.

1 solutions

Answer 252081 by josmiceli(9664) About Me  on 2010-10-06 14:03:43 (Show Source):
You can put this solution on YOUR website!
Let the speed of the passenger train = s
How much of a head start did the freight train get?
Let d%5B1%5D = headstart
d%5B1%5D+=+%28s+-+20%29%2A2
d%5B1%5D+=+2s+-+40
Start a stopwatch when the passenger train leave depot
In 3 hours the freight train goes a distance of
d%5B2%5D+=+%28s+-+20%29%2A3
d%5B2%5D+=+3s+-+60
Now the passenger train must travel d+=+d%5B1%5D+%2B+d%5B2%5D
in 3 hours
s%2A3+=+2s+-+40+%2B+3s+-+60
2s+=+100
s+=+50
The speed of the passenger train is 50 mi/hr
check:
s+-+20+=+30
d%5B1%5D+=+%28s+-+20%29%2A2
d%5B1%5D+=+60
d%5B2%5D+=+%28s+-+20%29%2A3
d%5B2%5D+=+90
d%5B1%5D+%2B+d%5B2%5D+=+150 mi
3s+=+150
s+=+50
OK


test/352683: It takes Juliana 3/4 hour to make a bracelet and 1 hour to make a necklace. She charges $50 for each bracelet and $80 for each necklace. Juliana works no more than 50 hours in one week and makes more than $1000. Write a system of inequalities to represent the combination of bracelets and necklaces. Help me!
1 solutions

Answer 252078 by josmiceli(9664) About Me  on 2010-10-06 13:48:40 (Show Source):
You can put this solution on YOUR website!
Let b = number of bracelets she makes in a week
Let n = number of necklaces she makes in a week
%283%2F4%29%2Ab+%2B+1%2An+%3C=+50
(1)3b+%2B+4n+%3C=+200
and, also
50b+%2B+80n+%3E+1000
(2)5b+%2B+8n+%3E+100


Travel_Word_Problems/352675: Find the cost per ounce of a sunscreen made from 100oz of a lotion that costs $2.50 per ounce and 50 oz of a lotion that costs $4.00 per ounce.

1 solutions

Answer 252074 by josmiceli(9664) About Me  on 2010-10-06 13:35:34 (Show Source):
You can put this solution on YOUR website!
Cost of $2.50/ounce lotion = 100%2A2.5+=+250
Cost of $4.00/ounce lotion = 50%2A4+=+200
Total cost of lotion = 200+%2B+250+=+450
Total ounces of lotion = 100+%2B+50+=+150
Cost per ounce = 450%2F150+=+3
The cost per ounce is $3


Linear-equations/352667: Here is the question.
A childs bank has only quarters and dimes, the total in the bank is $2.20. There are three times as many dimes as there are quarters. How many dimes are there and how many quarters are there?
the solution is written in the book, but I do not understand how the answer came to be.
0.25x + 0.10(3x) = 2.20
0.55x = 2.20
0.55x = 2.20
____ ____
0.55 0.55
x = 4 quarters
3x = 12 dimes
How did they come up with that answer? PLEASE HELP ME.
1 solutions

Answer 252068 by josmiceli(9664) About Me  on 2010-10-06 13:28:57 (Show Source):
You can put this solution on YOUR website!
I would have done it slightly different
I would say:
Let a = number of quarters
Let b = number of dimes
given:
(1) d+=+3q
(2) 10d+%2B+25q+=+220 (in cents)
Now, I substitute (1) in (2)
(2) 10%2A3q+%2B+25q+=+220
30q+%2B+25q+=+220
55q+=+220
q+=+4
and, since
d+=+3q
d+=+3%2A4
d+=+12
There are 12 dimes and 4 quarters



Linear-equations/352558: if it costs $20,000 to make 700 chairs and $30,000 to make 1500, write an equation that relates cost to number of chairs. what is the cost to make 2000 chairs
1 solutions

Answer 251954 by josmiceli(9664) About Me  on 2010-10-06 08:09:24 (Show Source):
You can put this solution on YOUR website!
Let C = cost, and plot on vertical axis
Let x = number of chairs, and plot on
horizontal axis
You are given 2 points on the graph,
(700, 20000) and (1500, 30000)
Use the point-slope formula

%28C+-+20000%29%2F+%28x+-+700%29+=+%2830000+-+20000%29+%2F+%281500+-+700%29
%28C+-+20000%29%2F+%28x+-+700%29+=+10000+%2F+800
%28C+-+20000%29%2F%28x+-+700%29+=+12.5
C+-+20000+=+12.5x+-+8750
C+=+12.5x+%2B+11250
T make 2000 chairs:
C+=+12.5%2A2000+%2B+11250
C+=+25000+%2B+11250
C+=+36250
It cost $36,250 to make 2000 chairs


Probability-and-statistics/352565: there were 200 raffle tickets sold. Jewel bought one ticket. What is her chance of winning expressed as a percent?
1 solutions

Answer 251950 by josmiceli(9664) About Me  on 2010-10-06 07:49:57 (Show Source):


Travel_Word_Problems/352564: A bus travelled 150 miles at a certain speed. If the bus went 10 miles faster, travel time will be decreased by 30 minutes. What is the speed of the bus?
1 solutions

Answer 251948 by josmiceli(9664) About Me  on 2010-10-06 07:47:47 (Show Source):
You can put this solution on YOUR website!
given:
d+=+150 mi
d+=+r%2At
150+=+r%2At
150+=+%28r+%2B+10%29%2A%28t+-+1%2F2%29
150+=+%28r+%2B+10%29%2A%28150%2Fr+-+1%2F2%29
150+=+150+%2B+1500%2Fr+-+r%2F2+-+5
1500%2Fr+-+r%2F2+-+5+=+0
1500+-+r%5E2%2F2+-+5r+=+0
r%5E2+%2B+10r+-+3000+=+0
Use quadratic formula:
r+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a+=+1
b+=+10
c+=+-3000
r+=+%28-10+%2B-+sqrt%28+10%5E2-4%2A1%2A%28-3000%29+%29%29%2F%282%2A1%29+
r+=+%28-10+%2B-+sqrt%28+100+%2B+12000%29+%29%29%2F2+
r+=+%28-10+%2B-+sqrt%2812100%29%29%2F2
r+=+%28-10+%2B+110%29%2F2
r+=+50
The negative square root cannot be a valid speed, so
The speed of the bus is 50 mi/hr
check answer:
150+=+%28r+%2B+10%29%2A%28t+-+1%2F2%29
150+=+%2850+%2B+10%29%2A%28t+-+1%2F2%29
150+=+60%2A%28t+-+1%2F2%29
150+=+60t+-+30
60t+=+180
t+=+3 hrs
and, since
150+=+r%2At
150+=+50%2A3
150+=+150
OK


Age_Word_Problems/352560: if peter is 7 years older than sharon and john is twice as old as peter, work out how old peter is if the average of their ages is 19
1 solutions

Answer 251940 by josmiceli(9664) About Me  on 2010-10-06 07:29:51 (Show Source):
You can put this solution on YOUR website!
Let p = Peter's age
Let s = Sharon's age
Let j = John's age
-----------------
given:
(1) p+=+s+%2B+7
(2) j+=+2p
(3) %28p+%2B+s+%2B+j%29%2F3+=+19
------------------
From (1):
p+=+s+%2B+7
s+=+p+-+7
Substitute (1) and (2) in (3)
(3) %28p+%2B+s+%2B+j%29%2F3+=+19
%28p+%2B+p+-+7+%2B+2p%29%2F3+=+19
%284p+-+7%29%2F3+=+19
4p+-+7+=+57
4p+=+64
p+=+16
Peter is 16
check answer:
s+=+p+-+7
s+=+9
and
j+=+2p
j+=+32
and
(3) %28p+%2B+s+%2B+j%29%2F3+=+19
(3) %2816+%2B+9+%2B+32%29%2F3+=+19
57%2F3+=+19
57+=+57
OK


Miscellaneous_Word_Problems/352561: Can you help me with this?
Using complete sentences, explain how to completely factor 3x2-3x-60.
(3x2 the 2 is smaller and elevated)
Thank you!
1 solutions

Answer 251937 by josmiceli(9664) About Me  on 2010-10-06 07:18:49 (Show Source):
You can put this solution on YOUR website!
[3x%5E2+-+3x+-+60]
Make the quadratic equal to zero
[3x%5E2+-+3x+-+60+=+0]
Divide both sides by 3
[x%5E2+-+x+-+20+=+0]
Add 20 to both sides
[x%5E2+-+x+=+20]
To complete the square, take one-half of the
x term, square the result, and add this
to both sides.
[x%5E2+-+x+%2B+%28-1%2F2%29%5E2+=+20+%2B+%28-1%2F2%29%5E2]
[x%5E2+-+x+%2B+1%2F4+=+80%2F4+%2B+1%2F4]
Express each side as a square.
[%28x+-+1%2F2%29%5E2+=+%289%2F2%29%5E2]
Take the square root of both sides
[x+-+1%2F2+=+9%2F2]
Subtract 9%2F2 from both sides
[x+-+5+=+0]
and
[x+-+1%2F2+=+-9%2F2]
Add 9%2F2 to both sides
[x+%2B+4+=+0]
The factors are x+-+5
and x+%2B+4


Evaluation_Word_Problems/352472: Please help me solve this equation:
Frank, Dawn and Robert went to the grocery store to purchase some sandwich meat. Frank bought 300 grams of ham and 200 grams of turkey breast for $8.90. Dawn bought 100 grams of ham and 300 grams of chicken breast for $9.00. Robert bought 200 grams of turkey breast and 200 grams of chicken breast for $9.40. What are the prices / 100 grams for ham, turkey breast and chicken breast?
Thanks so much!!
1 solutions

Answer 251874 by josmiceli(9664) About Me  on 2010-10-05 23:03:48 (Show Source):
You can put this solution on YOUR website!
Let a = price/100 grams ham
Let b = price/100 grams turkey breast
Let c = price/100 grams chicken breast
given:
(1) 3a+%2B+2b+=+890 (in cents)
(2) 1a+%2B+3c+=+900
(3) 2b+%2B+2c+=+940
---------------
There are 3 equations and 3 unknowns, so
it's solvable
Subtract (1) from (3)
(3) 2b+%2B+2c+=+940
(1) -3a+-+2b+=+-890
2c+-+3a+=+50
2c+=+3a+%2B+50
c+=+%281%2F2%29%2A%283a+%2B+50%29
Substitute this in (2)
a+%2B+%283%2F2%29%2A%283a+%2B+50%29+=+900
2a+%2B+9a+%2B+150+=+1800
11a+=+1650
a+=+150
Substitute this in (2)
(2) 1a+%2B+3c+=+900
150+%2B+3c+=+900
3c+=+750
c+=+250
Substitute in (3)
(3) 2b+%2B+2%2A250+=+940
2b+=+940+-+500
2b+=+440
b+=+220
$1.50 = price/100 grams ham
$2.20 = price/100 grams turkey breast
$2.50 = price/100 grams chicken breast


Mixture_Word_Problems/350130: A bottle contains 850 mL of fruit punch with a concentration of 50% pure fruit juice. Jill drinks 100 mL of the punch and then refills the bottle with an equal amount of a cheaper brand of punch. If the concentration of juice in the bottle is now reduced to 48%, what was the concentration in the punch that Jill added?
1 solutions

Answer 250261 by josmiceli(9664) About Me  on 2010-09-30 10:43:35 (Show Source):
You can put this solution on YOUR website!
The answer in words will be:
(ml of pure juice she ends up with)/(total ml of punch) = 48%
Let x = ml of pure juice in punch she added
Given:
850+-+100+=+750 ml of 50% punch at start
.5%2A750+=+375 ml of pure juice at start
-----------------------------------------------
%28375+%2B+x%29%2F850+=+.48
x%2F100 = concentration of punch added
375+%2B+x+=+.48%2A850
x+=+408+-+375
x+=+33 ml
33%2F100+=+.33
The concentration of the punch she adds must be 33%


Money_Word_Problems/350131: How long will it take P dollars to triple itself at 14% simple interest?
1 solutions

Answer 250252 by josmiceli(9664) About Me  on 2010-09-30 10:25:55 (Show Source):
You can put this solution on YOUR website!
I will say that t is the number of years for
P dollars to triple at an annual rate of 14%
3P+=+P%2A%281+%2B+.14t%29
3+=+1+%2B+.14t
+.14t+=+3+-+1
t+=+2%2F.14
t+=+14.286
This is about 14 yrs and 3 1/2 months



Travel_Word_Problems/349632: Allison and Rachel are taking a trip together. They decide to share the driving responsibilities for the 480 mile drive. Allison drove at an average rate of 50 mph and Rachel drove at an average rate of 40 mph. If Allison drover 45 minutes more than Rachel, then how far did Rachel drive?
1 solutions

Answer 249922 by josmiceli(9664) About Me  on 2010-09-29 12:15:28 (Show Source):
You can put this solution on YOUR website!
For Allison:
d+=+r%2At
d+=+50t
For Rachel:
480+-+d+=+40%2A%28t+-+3%2F4%29
----------------------
By substitution:
480+-+50t+=+40t+-+30
90t+=+510
t+=+5.667
d+=+50t
d+=+283.333
Rachel drove:
480+-+283.333+=+196.667 mi
check answer:
480+-+d+=+40%2A%28t+-+3%2F4%29
480+-+283.333+=+40%2A%285.667+-+.75%29
196.667+=+40%2A4.9167
196.667+=+196.667


Probability-and-statistics/349662: 1300 x (1+.0925) to the 35th power
1 solutions

Answer 249919 by josmiceli(9664) About Me  on 2010-09-29 12:03:31 (Show Source):
You can put this solution on YOUR website!
You can do this with logs:
1300%2A1.0925%5E35
Take the log. Note that the log of a product
is the sum of the logs of the factors
log%281300%29+%2B+35%2Alog%281.0925%29
log%2813%2A100%29+%2B+35%2Alog%281.0925%29
log%2813%29+%2B+log%28100%29+%2B+35%2Alog%281.0925%29
1.1139+%2B+2+%2B+35%2A.0384
3.1139+%2B+1.3448
4.4587
This is the log of the answer.
Now you have to find 10%5E4.4587
which is the antilog
10%5E4.4587+=+28754.1




Word_Problems_With_Coins/349652: What combinations of nickels and dimes total 45cents if the number of nickels is at least as great as the number of dimes? Algebra 2 question
1 solutions

Answer 249917 by josmiceli(9664) About Me  on 2010-09-29 11:52:30 (Show Source):
You can put this solution on YOUR website!
3 nickels and 3 dimes = 45 cents
5 nickels and 2 dimes = 45 cents
7 nickels and 1 dime = 45 cents
Note that the number of nickels must be odd,
since that's the only way to get 45 cents


Expressions-with-variables/349322: -7(3+2x) = 84
Im horrible at math and my teacher hates me.. :'( help.
1 solutions

Answer 249736 by josmiceli(9664) About Me  on 2010-09-28 17:58:06 (Show Source):
You can put this solution on YOUR website!
You need consoling:
Being bad at math is like being a bad driver.
You're just not doing what the other drivers do
that make them good drivers. The teacher is mad
because you keep driving her car off a cliff.
All I can say is math never strays far from the
basics, and if you missed the basics somehow,
you have to back there- like back to parallel
parking. Don't worry if you're too young to drive-
I'm just using examples.
You're not born to be bad at math- you just got that
way
-7%283%2B2x%29+=+84
You MUST do the same thing to both sides of an equation
Divide both sides by -7
%28%28-7%29%2F%28-7%29%29%2A%283+%2B+2x%29+=+84%2F%28-7%29
3+%2B+2x+=+-12
Now subtract 3 from both sides
3+-+3+%2B+2x+=+-12+-+3
2x+=+-15
Divide both sides by 2
x+=+-7.5
Keep at it.


Mixture_Word_Problems/349274: pure acid is to be added to a 10% solution to obtain 45L of a 40% acid solution. What amounts of each should be used?
1 solutions

Answer 249720 by josmiceli(9664) About Me  on 2010-09-28 16:33:51 (Show Source):
You can put this solution on YOUR website!
Let a = liters of pure acid to be added
Let b = liters of 10% solution to be added
given:
(1) a+%2B+b+=+45
%28a+%2B+.1b%29%2F45+=+.4
a+%2B+.1b+=+18
(2) 10a+%2B+b+=+180
Subtract (1) from (2)
(2) 10a+%2B+b+=+180
(1) -a+-+b+=+-45
9a+=+135
a+=+15
From (1),
b+=+45+-+15
b+=+30
15 liters of pure acid and 30 liters of 10% acid solution must be mixed


real-numbers/349256: please tell me how to do square roots of nehative numbers
1 solutions

Answer 249714 by josmiceli(9664) About Me  on 2010-09-28 16:25:57 (Show Source):
You can put this solution on YOUR website!
Square roots of negative numbers are called imaginary
numbers. A complex number has an imaginary part
which includes sqrt%28-1%29 and a real part which is
just an ordinary number.
The complex numbers are plotted on what is called the
complex plane. If this is too much, just remember
i+=+sqrt%28-1%29
i%5E2+=+-1
i%5E3+=+-sqrt%28-1%29
i%5E4+=+%2B1
and this cycle just repeats over and over
You can turn any square root of a negative number
into a number times sqrt%28-1%29, as follows:
sqrt%28-47%29+=+sqrt%2847%29%2Asqrt%28-1%29
+sqrt%2847%29%2Asqrt%28-1%29+=+sqrt%2847%29%2Ai
or
sqrt%28-81%29+=+3%2Asqrt%28-1%29
3%2Asqrt%28-1%29+=+3i


Percentage-and-ratio-word-problems/349262: What is the percentage of girls if you have 11 students, 7 are girls and 4 are boys?
1 solutions

Answer 249706 by josmiceli(9664) About Me  on 2010-09-28 16:14:41 (Show Source):


Exponential-and-logarithmic-functions/349244: Please anyone I need your help

A store offers two payment plans. Under the installment plan, you pay 25% down and 25% of the purchase price in each of the next 3 years. If you pay the entire bill immediately, you can take a 10% discount from the purchase price.
Which is a better deal if you can borrow or lend funds at a 5% interest rate?
1 solutions

Answer 249699 by josmiceli(9664) About Me  on 2010-09-28 16:02:27 (Show Source):
You can put this solution on YOUR website!
I'll say the purchase price is p
Installment plan:
25% down leaves .75p left to pay off in 3 years
Entire bill plan:
p+-+.1p+=+.9p You pay 90% of the bill immediately
---------------------
The 2nd plan puts .1p in your pocket immediately
With the 1st plan, you can invest .75p at 5% the 1st
year, which is .05%2A.75+=+.0375p
The 2nd year, you have .5p to invest at 5%, which is
.05%2A.5p+=+.025p
The 3rd year, you have .25p to invest at 5%, which is
.05%2A.25p+=+.0125p
Adding these for the 3 years, I get .0375p+%2B+.025p+%2B+.0125p+=+.075p
This looks like the 2nd plan wins, since
.1p is greater than .075p


Linear-systems/349181: The concession stand sells hot dogs and drinks during their high school foot ball game. John bought 6 hot dogs and 4 drinks and paid $6.70. Jessica bought 4 hot dogs and 3 drinks and paid $4.65. What is the price of a hot dog?
1 solutions

Answer 249621 by josmiceli(9664) About Me  on 2010-09-28 13:02:44 (Show Source):
You can put this solution on YOUR website!
Let a = price of 1 hotdog (in cents)
Let b = price of 1 drink (in cents)
given:
For John:
(1) 6a+%2B+4b+=+670
For Jessica:
(2) 4a+%2B+3d+=+465
Multiply both sides of (1) by 3
and both sides of (2) by 4
Then subtract (2) from (1)
(1) 18a+%2B+12b+=+2010
(2) -16a+-+12d+=+-1860
2a+=+150
a+=+75
Then, from (1)
(1) 6%2A75+%2B+4b+=+670
450+%2B+4b+=+670
4b+=+220
b+=+55
The price of a hotdog is 75 cents


Mixture_Word_Problems/349169: Pure acid is to be added to a 5% acid solution to obtain 95L if 80% solution. What amounts of each should be used?
1 solutions

Answer 249616 by josmiceli(9664) About Me  on 2010-09-28 12:53:20 (Show Source):
You can put this solution on YOUR website!
Let aliters = amount of pure acid to be added
Let bliters = amount of 5% solution needed
In words:
(total liters of acid in final solution)/(total liters of final solution)
= 80%
----------------------
given:
(1) a+%2B+b+=+95
%28a+%2B+.05b%29%2F95+=+.8
a+%2B+.05b+=+76
(2) 100a+%2B+5b+=+7600
Multiply both sides of (1) by 5 and
subtract from (2)
(2) 100a+%2B+5b+=+7600
(1) -5a+-+5b+=+-475
95a+=+7125
a+=+75
b+=+95+-+75
b+=+20
75 liters of pure acid and 20 liters of 5% acid solution are needed
check answer:
%28a+%2B+.05b%29%2F95+=+.8
%2875+%2B+.05%2A20%29%2F95+=+.8
%2875+%2B+1%29%2F95+=+.8
76%2F95+=+.8
76+=+76
OK


Percentage-and-ratio-word-problems/349037: Last year a small college accepted 363 students out
of the 1340 people that applied. If the college
accepted 30% of the female applicants and 25% of
the male applicants, how many women applied?
1 solutions

Answer 249490 by josmiceli(9664) About Me  on 2010-09-28 04:00:14 (Show Source):
You can put this solution on YOUR website!
Let m = number of men that applied
Let w = number of women that applied
given:
(1) m+%2B+w+=+1340
.25m+%2B+.3w+=+363
-----------------------
(2) 25m+%2B+30w+=+36300
Multiply both sides of (1) by
25 and subtract from (2)
(2) 25m+%2B+30w+=+36300
(1) -25m+-+25w+=+-33500
5w+=+2800
w+=+560
m+=+1340+-+560
m+=+780
560 applicants were women



Percentage-and-ratio-word-problems/349038: The local coffee shop combines two kinds of beans
to make a blended mixture of beans. If Ethiopian
Harrar beans cost $7.25 per pound, and Arabian
Mocha beans cost $13.70 per pound, how many
pounds of each should be used to make 3 pounds of
a blend that costs $10.26 per pound?
1 solutions

Answer 249489 by josmiceli(9664) About Me  on 2010-09-28 03:51:05 (Show Source):
You can put this solution on YOUR website!
Let e = pounds of E. H. beans needed
Let a = pounds of A. M. beans needed
given:
(1) e+%2B+a+=+3
cost of e is 7.25e
cost of a is 13.7a
-----------------------------
(2) 7.25e+%2B+13.7a+=+3%2A10.26
(2) 7.25e+%2B+13.7a+=+30.78
Multiply both sides of (1) by 7.25
and subtract from (2)
(2) 7.25e+%2B+13.7a+=+30.78
(1) -7.25e+-+7.25a+=+-21.75
6.45a+=+9.03
a+=+1.4
e+=+3+-+1.4
e+=+1.6
1.4 pounds of A.M. and 1.6 pounds of E. H. are needed


Probability-and-statistics/349042: I have an issue with this problem for my probablity and statistics class. I hope you can help.
You are dealt two cards successively from a deck of 52 playing cards. Find the probability that both cards are black in a simplified fraction.
How is the problem figured out - the answer is 25/102
Please help : )
1 solutions

Answer 249487 by josmiceli(9664) About Me  on 2010-09-28 03:24:40 (Show Source):
You can put this solution on YOUR website!
I found a way to get that answer. I'm not
positive it's right.
B = black
R = red
The cards drawn can be
BB
BR
RB
RR
The different ways to get BB or RR are
%2826%2F52%29%2A%2825%2F52%29
The different ways to get BR or RB are
%2826%2F52%29%2A%2826%2F52%29
My fraction should be BB / (BB + BR + RB + RR) =
%28%2826%2A25%29%2F52%5E2%29+%2F+%282%2A%28%2826%2A25%29%2F52%5E2+%2B+26%5E2%2F52%5E2%29%29 =
%2826%2A25%29+%2F+%282%2A%2826%2A25+%2B+26%2A26%29%29 =
25%2F%282%2A%2825+%2B+26%29%29 =
25+%2F+%282%2A51%29
25%2F102



Equations/349048: To make an international telephone call, you need the code for the country you are calling. The codes for Belgium, France, and Spain are three consecutive integers whose sum is 99. Find the code for each country.
1 solutions

Answer 249486 by josmiceli(9664) About Me  on 2010-09-28 02:54:35 (Show Source):
You can put this solution on YOUR website!
Call the consecutive integers n, n%2B1, n%2B2
given:
n+%2B+n+%2B+1+%2B+n+%2B+2+=+99
3n+%2B+3+=+99
3n+=+96
n+=+32
The codes for the 3 countries are 32, 33, and 34


Miscellaneous_Word_Problems/348728: The circumference of a rear wheel of a certain wagon is 3 feet longer than the circumference of the front wheel. The rear wheel makes 100 fewer revolutions than the front wheel in travelling a distance of 6000 feet, Find the circumference of each wheel.
1 solutions

Answer 249349 by josmiceli(9664) About Me  on 2010-09-27 16:51:27 (Show Source):
You can put this solution on YOUR website!
Let c = circumference of the front wheel
Then c+%2B+3 = circumference of the rear wheel
When the front wheel travels 6000 ft, it makes
6000%2Fc revolutions
The rear wheel makes 6000%2Fc+-+100 revolutions
--------------------------------------
%286000%2Fc+-+100%29%2A%28c+%2B+3%29+=+6000
This says:
(revolutions of rear wheel) x(circumference of rear wheel) = distance traveled
6000+-+100c+%2B+18000%2Fc+-+300+=+6000
6000c+-+100c%5E2+%2B+18000+-+300c+=+6000c
100c%5E2+%2B+300c+-+18000+=+0
c%5E2+%2B+3c+-+180+=+0
Completing the square:
c%5E2+%2B+3c+%2B+%283%2F2%29%5E2+=+180+%2B+%283%2F2%29%5E2
c%5E2+%2B+3c+%2B+9%2F4+=+720%2F4+%2B+9%2F4
%28c+%2B+3%2F2%29%5E2+=+729%2F4
c+%2B+3%2F2+=+27%2F2
c+=+24%2F2
c+=+12
c+%2B+3+=+15
The front wheel is 12 ft in circumference
The rear wheel is 15 ft in circumference
check:
%286000%2Fc+-+100%29%2A%28c+%2B+3%29+=+6000
%286000%2F12+-+100%29%2A%2812+%2B+3%29+=+6000
%28500+-+100%29%2A15+=+6000
400%2A15+=+6000
6000+=+6000