SOLUTION: A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 45% salt and Solution B is 70% salt. She wants to o

Algebra ->  Finance -> SOLUTION: A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 45% salt and Solution B is 70% salt. She wants to o      Log On


   



Question 1025706: A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 45% salt and Solution B is 70% salt. She wants to obtain 70 ounces of a mixture that is 55% salt. How many ounces of each solution should she use?
solution A = x ounces
Solution B = x ounces
thank you to whoever answers :)

Found 5 solutions by josgarithmetic, lwsshak3, MathTherapy, ikleyn, greenestamps:
Answer by josgarithmetic(39818) About Me  (Show Source):
You can put this solution on YOUR website!
x, how many ounces of 45% solution;
70-x, how many ounces of 70% solution;
Just to inform you, these concentrations of salt are meaningless because they are impossible. IF you had them in water solution... but they could be physical mixtures in some powder material.

%2845x%2B70%2870-x%29%29%2F70=55

9x%2B14%2870-x%29=70%2A11

9x%2B980-14x=770

-5x=770-980

x=%28980-770%29%2F5

x=210%2F5

x=42

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 45% salt and Solution B is 70% salt. She wants to obtain 70 ounces of a mixture that is 55% salt. How many ounces of each solution should she use?
solution A = x ounces
Solution B = x ounces
let x=Amt of solution A used
70-x=Amt of solution B used
45%x+70%(70-x)=55%*70
.45x+49-.7x=38.5
.25x=10.5
x=12
70-x=58
Amt of solution A used=12 ounces
Amt of solution B used=58 ounces

Answer by MathTherapy(10837) About Me  (Show Source):
You can put this solution on YOUR website!

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 45% salt and Solution B is 70% salt. She wants to obtain 70 ounces of a mixture that is 55% salt. How many ounces of each solution should she use?
solution A = x ounces
Solution B = x ounces
thank you to whoever answers :)
 


Answer by ikleyn(53846) About Me  (Show Source):
You can put this solution on YOUR website!
.
A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt.
She knows that Solution A is 45% salt and Solution B is 70% salt. She wants to obtain 70 ounces of a mixture
that is 55% salt. How many ounces of each solution should she use?
~~~~~~~~~~~~~~~~~~~~~~


        Calculations in the post by @lwsshak3 are incorrect, giving wrong answer.
        I came to bring a correct solution.


solution A = x ounces
Solution B = (70-x) ounces
let x = Amt of solution A used
70-x = Amt of solution B used
0.45x + 0.7*(70-x) = 0.55*70
0.45x + 49 - 0.7x = 38.5
0.25x = 10.5
x = 10.5/0.25 = 42.
70-x = 28
Amt of solution A used = 42 ounces
Amt of solution B used = 28 ounces

CHECK   for the final concentration     %280.45%2A42+%2B+0.7%2A28%29%2F70 = 0.55, or 55%.     ! precisely correct !

Solved correctly.



Answer by greenestamps(13351) About Me  (Show Source):
You can put this solution on YOUR website!


Here is a solution using a non-traditional method that can be used to solve any 2-part mixture problem. This method can be especially fast and easy if the numbers in the problem are "nice" (which in this problem they are....)

(1) Use a number line if it helps to observe/calculate that 55% is 10/25 = 2/5 of the way from 45% to 70%.
(2) That means 2/5 of the mixture must be the 70% salt solution.

2/5 of 70 ounces is 28 ounces.

ANSWER: 28 ounces of the 70% solution and 70-28 = 42 ounces of the 45% solution.