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josmiceli answered: 9658 problems
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Answer 165990 by josmiceli(9661) on 2009-10-04 01:21:56 (Show Source):
You can put this solution on YOUR website!Let  = tons of $125/ton hay used
Let  = tons of $75/ton hay used
given:
(1) 
(2) 
---------------------------
Multiply both sides of (1) by  and
subtract from (2)
(2) 
(1)

and, since

30 tons of $125/ton hay and 70 tons of $75/ton hay
must be purchased
check:
(2)

OK
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Linear-equations/221111: x=number of white paint can
y=number of blue paints can
x=y=5 cans of paint
white paint = $ 24
blue paint = $ 28
24x + 28y = $132
How do you solve: 24x + 28y = 132 ?
How steps. 1 solutions
Answer 165891 by josmiceli(9661) on 2009-10-03 17:24:19 (Show Source):
You can put this solution on YOUR website!You can't solve it. There are 2 variables, x and y,
so you need 2 equations to solve.
You wrote
 . I think you mistyped & actually
meant 
That's your other equation
Multiply both sides of this equation by

Now subtract it from the other equation

and, since

Hope this helps
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Permutations/220982: A single die is rolled twice. Find the probability of rolling an odd number the first time and a number less than 3 the second time.
thank you for your help! 1 solutions
Answer 165777 by josmiceli(9661) on 2009-10-03 11:44:02 (Show Source):
You can put this solution on YOUR website!The 6 sides of the die are numbered 1,2,3,4,5,6
There are 3 odd and 3 even numbers
probability of an odd number on 1st roll is

When you want A AND B probabilities, you multiply
the events A and B
The number less than 3 are 1,2, so the probability is

And the probability of getting both these events is
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Quadratic_Equations/220887: I don't understand how to use the formula of ax^+bx+c=0
My problem is this x^2+7x=180
I need x answered 1 solutions
Answer 165739 by josmiceli(9661) on 2009-10-03 01:07:38 (Show Source):
You can put this solution on YOUR website!The equation is called quadratic, or 2nd degree.
When you plot it on a graph, it's called a parabola.
It's in the form  , but first
subtract  from both sides, and it will be in
that form

Matching it up with the general equation,

Now use the quadratic formula to solve

769 isn't a perfect square- are you sure you
copied this right?
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Miscellaneous_Word_Problems/220907: When the Johnson triplets were three weeks old, their sleep habits were remarkably consistent. John slept for 3 hours and was awake for 30 minutes. Joan slept for 2 hours and was awake for 30 minutes. Jane slept for 2 hours 20 minutes and was awake for 40 minutes. On October 13 at 8:00 P.M., they all went to sleep at the same time. When did this event occur again? Give both the date and time.
1 solutions
Answer 165737 by josmiceli(9661) on 2009-10-03 00:55:49 (Show Source):
You can put this solution on YOUR website!Each one has a different sleep-awake cycle:
John's is
 hrs
Joan's is
 hrs
Jane's is
 hrs
Call the lengths of these cycles  ,  , and 
Now I can say

Note that  , and

Finally, I can say

60 sleep-awake cycles for John, 84 sleep-awake cycles for Joan
and 70 sleep-awake cycles for Jane all end together 210 hours
from Oct 13, 8 PM
 days
and
 hours
8 days would make it Oct 21, 8 PM
Adding 18 hours makes it
Oct 22, 2 PM they all go to sleep again at the same time
check answer
For John:

OK
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Exponents-negative-and-fractional/220863: i don't get negative numbers please explain 1 solutions
Answer 165689 by josmiceli(9661) on 2009-10-02 19:46:10 (Show Source):
You can put this solution on YOUR website!Sometime a negative number seems like a ghost
and sometimes it's clearly visible.
It depends on what you're using them for.
(A)
Let's say I'm on a railroad track that runs east and west.
If I want to, I can say that if I go west, that's positive
motion, and if I go east, that's negative motion.
OK, I go W 1 mile, I go E 2 miles, then I go W 6 miles.
How far am I from where I started?
I went W +1 miles
I went E -2 miles
I went W +6 miles
1 - 2 + 6 = +5 miles
I am 5 miles west of where I started.
(B)
Let's say I owe you $5. I've got the $5, so
it's a (+) on my records until it's spent.
You're missing the $5, so it's a (-) on your
records until I pay it back.
What does -$5 look like? Nobody's ever seen one,
but recordkeeping can't work without it.
Think of it as an empty pocket that only holds
a single $5 bill, and you're always reminded
that it's empty and needs to be filled.
It's the -$5 pocket.
Does that help at all? You need to keep
thinking about it.
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Systems-of-equations/220821: this is a word problem i cant figure it out please help: one canned juice drink is 20% orange juice, another os 10% orange juice. How many liters pf each should be mixed togethre in order to get 10L that is 12% orange juice? 1 solutions
Answer 165686 by josmiceli(9661) on 2009-10-02 19:24:06 (Show Source):
You can put this solution on YOUR website!Let  = liters of 20% juice needed
Let  = liters of 10% juice needed
given:
(1)  liters of 12% mixture
OJ in 20% juice is  liters
OJ in 10% juice is  liters
OJ in 12% juice is  liters
In words:
(liters OJ in 20% mix + liters OJ in 10% mix)/(total liters of 12% mix) = 12%

(2) 
Subtract (1) from (2)
(2) 
(1)
 liters
and, since
 liters
2 liters of the 20% juice and 8 liters of the 10%
juice need to be mixed
check answer:

OK
|
Miscellaneous_Word_Problems/220828: I'm taking algebra but I have a hard time with word problems. Please help.
1) A certain granola mixture is 10% peanuts.
A) If a container has 20 lbs. of granola how many pounds of peanuts does it contain?
B) If a container has X lbs. of granola in it write an expression for the amount of peanuts it contains.
Thank you for any help!
1 solutions
Answer 165681 by josmiceli(9661) on 2009-10-02 17:59:41 (Show Source):
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Quadratic_Equations/220641: Sammy spends 10 Euros on some cans of drink. In another shop she sees that the same cans are each 10 cents cheaper, and she calculates that she could have brought 5 more cans for the same money. How many cans did she buy? 1 solutions
Answer 165604 by josmiceli(9661) on 2009-10-02 10:09:36 (Show Source):
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Linear-equations/220660: I have word problem.
A medium pizza costs $10.95, a large pizza costs $14.95. On a given day 50 pizzas were sold at a cost of $663.50. How many medium and how many large pizzas were sold.
How do I set this up
thanks. 1 solutions
Answer 165597 by josmiceli(9661) on 2009-10-02 09:36:12 (Show Source):
You can put this solution on YOUR website!Let  = number of medium pizzas sold
Let  = number of large pizzas sold
given:
(1)
 = cash received for  pizzas (in cents)
------------------
 = cash from medium pizzas (in cents)
 = cash from large pizzas (in cents)
(2) 
I have 2 equations with 2 unknowns, so it's solvable
Multiply both sides of (1) by  and subtract
from (2)
(2) 
(1)

and, since
(1)

21 medium and 29 large pizzas were sold
check answer:
(2)

OK
|
Travel_Word_Problems/220538: Rick robbed a bank and left town at 64 mph. His crime was discovered 45 minutes later when the sheriff took off in hot pursuit at 80 mph. How long until the sheriff catches up? 1 solutions
Answer 165544 by josmiceli(9661) on 2009-10-01 22:39:33 (Show Source):
You can put this solution on YOUR website!Assume I have a stopwatch. I will start the stopwatch
when the sheriff leaves. At that time, Rick has travelled
 (45 min is 3/4 of an hour)
 mi
So, Rick has a 48 mi headstart
From this headstart to where the sheriff catches him,
call  in miles
For the sheriff:

For Rick:

By substitution:
 hrs
The sheriff catches him 3 hrs after the sheriff leaves town
check answer:
 (for Rick)
 mi
So, Rick went a total of  mi at  mi/hr
The sheriff went  mi also at  mi/hr
For Rick:
 hrs for the whole trip for Rick
For Sheriff:
 hrs for the whole trip for Sheriff
Note that  , which is
the 45 min headstart that Rick had
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Money_Word_Problems/220551: At the Glamour Boutique, a bottle of Allura Numero 75 perfume costs as much as two bottles of Exotic Mist. Mrs. Hampton bought one bottle of each and paid $24.00. How much does a bottle of Allura cost? 1 solutions
Answer 165535 by josmiceli(9661) on 2009-10-01 22:15:58 (Show Source):
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Travel_Word_Problems/220543: I need help solving the problem:
The Great Seto Bridge in Japan is about 7.6 mi long. How long would it take you to cross the bridge if you were walking at 3mi/hr?
This is what I have done:
I set up a chart:
Rate:4 Time:t Distance:7.6
So would it be 4t=7.6?
I have no idea what I am doing. Please help. Your guidance would be greatly appreciated.
Thank you.
-Michelle
(Freshman) 1 solutions
Answer 165531 by josmiceli(9661) on 2009-10-01 22:09:42 (Show Source):
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Mixture_Word_Problems/220473: Help with word problem for Algebra 1
The nutty food company sells trail mixes by the pound. There are peanuts, raisin, ans carob-coated pretzels. The mgr. wants to make 80 pounds of this mixture and sell it for $3.35 per pound. Peanuts sell for $ $3.20 per pound, raisins sell for $ 2.40 per pound, and the carob pretzels sell for for $4.00 per pound. If the mixture has TWICE as many pounds of pretzels as raisons, how many pounds of each ingredient should the clerk use? 1 solutions
Answer 165527 by josmiceli(9661) on 2009-10-01 22:03:54 (Show Source):
You can put this solution on YOUR website!Let  = pounds of peanuts needed
Let  = pounds of raisins needed
Let  = pounds of carob pretzels needed
given:
(1) 
(2) 
(2) 
Cost of peanuts in mixture = 
Cost of raisins in mixture = 
Cost of Carob pretzels in mixture = 
--------------------------------------------
(3) 
(3)  (units are cents)
Multiply both sides of (1) by  and
subtract from (3)
(3) 
(1)

Divide both sides by

Substitute this result and (2) in (1)
(1)

and

and

The clerk should use 35 lbs of peanuts, 15 lbs of raisins,
and 30 lbs of carob-coated pretzels
check answer:

OK
|
Money_Word_Problems/220203: A bookstore priced all hardback books at $5 a book and all paper back books at $1. The store sold 30 more paper backs than hardbacks. Total sales were $354. How many of each type were sold. 1 solutions
Answer 165394 by josmiceli(9661) on 2009-10-01 13:55:39 (Show Source):
You can put this solution on YOUR website!Let  = number of hardbacks soold
Let  = number of paperbacks sold
given:

(1) 
and
(2) 
Multiply both sides of (1) by  and add to (2)

and

84 paperbacks and 54 hardcovers were sold
check answer:
(2)

OK
|
Money_Word_Problems/220231: I know the answer is 2014. I just don't understand how this was calculated. Please help me.
Sonja and Chris both accept new jobs on March 1, 2001. Sonja starts at $44,000 with a raise each March 1 of 2%. Chris starts at $28,000 with a raise on March 1 each year of 6%. In what year will Chris' salary exceed Sonja's? 1 solutions
Answer 165391 by josmiceli(9661) on 2009-10-01 13:45:29 (Show Source):
You can put this solution on YOUR website!The situation can be modelled as 2 linear equations
Let Salary,  , be plotted on the vertical axis
Let Years,  , be plotted on the horizontal axis (staring at zero)
For Sonja,
(1) 
For Chris,
(2) 
I can rewrite them as
(1) 
(2) 
I'll find out in what year Salaries are equal

Divide both sides by 28000

Their salaries will be equal in 20 years
Chris's will exceed Sonja's in 21 years,
or March 1st, 2022.
If you're sure the answer is 2014, then I made a
mistake, but I think the method is OK.
I'll plot them:
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Triangles/220233: Find the altitude of an equilateral triangle that has side lengths of 4y. Express your answer in simplest radical form.
I am a homeschooling mom and don't remeber how to do this. Our book doesnt help either. 1 solutions
Answer 165378 by josmiceli(9661) on 2009-10-01 13:11:33 (Show Source):
You can put this solution on YOUR website!The interior angles of an equilateral triangle
are 60-60-60, which adds up to
180 degrees, as they should.
The altitude divides the triangle into two
30-60-90 triangles, with the altitude being
opposite the 60 degree angle.
Call the altitude 
In this right triangle,  ,
and

Solve for
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Probability-and-statistics/220227: Two cards are drawn in succession from an ordinary deck of 52 bridge cards without replacement of the first card. Find the probability that both cards are a Queen.
1 solutions
Answer 165376 by josmiceli(9661) on 2009-10-01 12:58:18 (Show Source):
You can put this solution on YOUR website!There are 4 queens, so on the 1st draw
the probability of getting one is

Now there are  cards in the deck,
and if you got a queen, there are 3 queens left
The probability of getting one is

When you want the probability of getting A and B
you multiply, so

The probability of drawing 2 queens in a row is 1/221
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Mixture_Word_Problems/220223: I can't figure this one out and it's due yesterday! please help! i can do the conversion part, but factoring in the '18%' is stumping me...
thank you!
{{You work in a factory that makes chocolate chip cookies. Your cookies contain 18% by weight chocolate chips. If your boss tells you that yesterday, the factory used up 300 lbs. of chocolate chips, how many kilograms of cookies did the factory make?}} 1 solutions
Answer 165375 by josmiceli(9661) on 2009-10-01 12:49:54 (Show Source):
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Travel_Word_Problems/219900: One lawn care woker can mow 3 lawns in 60 min. and another can mow 5 lawns in 75 min. How long will it take them to mow 7 lawns together? 1 solutions
Answer 165251 by josmiceli(9661) on 2009-09-30 20:18:08 (Show Source):
You can put this solution on YOUR website!This is a rate problem
In general:
(1st worker's rate) + (2nd worker's rate) = (rate working together)
given:
1st worker's rate =  lawns/min
2nd worker's rate =  lawns/min

Multiply both sides by
 min
It takes them 1 hr to mow 7 lawns working together
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Equations/219890: i am really struggeling e=wtih my homework.
i am in 7th grade and in pre-algebra
my question is that i need a algebra equation that EQUALS 29
and only using A,B,C,D EACH ONLY ONCE.
A=1
B=2
C=3
D=4 FOR EXAMPLE:
(bc)+dxa
2x3=6+4=10x1= 10
so the answer would be 10 1 solutions
Answer 165246 by josmiceli(9661) on 2009-09-30 20:09:55 (Show Source):
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Mixture_Word_Problems/219575: Hi, I have a solution/miture question. I can solve the problem just fine once I get it in the right order... but this one I'm having a hard time putting all the info where it belongs.
Q) A pharmacist has 20L of a 10% drug solution. How many liters of 5% solution must be added to get a mixture that is 8%?
If you could just help me get this in the right format I would would be so thankful!! Thanks!!!
Casie R 1 solutions
Answer 165101 by josmiceli(9661) on 2009-09-30 14:11:31 (Show Source):
You can put this solution on YOUR website!Let  = liters of 5% solution to be added
It doesn't say what the drug is mixed with, so I'll
just call it water.
In words:
(liters of drug in final solution)/(liters of drug + water in final solution) = 8%
given:
In  liters of 10% solution, there is
 liters of drug
In  liters of the 5% solution there is
 liters of drug
-------------------------

The Pharmacist must add 13.333 liters of the 5% solution
check answer

(error due to rounding -OK)
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Expressions-with-variables/219570: A rubber ball is dropped from the height of 13.5 feet. After each bounce the ball only goes up by 60% of what it did on the previous bounce. How high will the ball go after the 38th bounce? I took the 13.5x .6 for the 1st bounce which is 8.1Ft. and the 2nd bounce is 4.9ft. and the third is 2.9ft. I could do this for all the bounces but it would take me forever. How can I write a formula to just put in bounce to get height? 1 solutions
Answer 165092 by josmiceli(9661) on 2009-09-30 13:54:37 (Show Source):
You can put this solution on YOUR website!I'll try to write a general formula.
After the 1st and succeeding bounces,

It looks like the formula would be
 where  is the number of bounces
and  is the height after that bounce
After  bounces,
 ft
How much is that in millionths of an inch?
 millionths of inch/ft

That looks like  billionths
of an inch after the 38th bounce
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Probability-and-statistics/219499: A car radiator contains 10 liters of 20% anitfreeze solution. How many liters of pure antifreeze are needed to make the solution 50% antifreeze without replacement? 1 solutions
Answer 165054 by josmiceli(9661) on 2009-09-30 11:54:12 (Show Source):
You can put this solution on YOUR website!This assumes that the radiator will hold whatever added
antifreeze you try to put in.
In words:
(final liters of antifreeze)/(final liters of total mixture) = 50%
Let  = liters of antifreeze to be added

Multiply both sides by

6 liters of antifreeze needs to be added to make mixture 50%
check answer:

OK
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Money_Word_Problems/219496: How long does it take your money in your savings account to double at 8% interest rate using the formula A=Pe^rt ? 1 solutions
Answer 165052 by josmiceli(9661) on 2009-09-30 11:45:09 (Show Source):
You can put this solution on YOUR website!
 is the original amount invested. The problem
wants to know how long (what  is) it takes to
make  twice this amount, so

given:
 (this is annual intest rate)

Divide both sides by

Take the natural log of both sides
 (  is the time in years)
I can find  years in months also
 (about 8 months)
It takes 8 years and 8 months to double money
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