my question is in the description since i cant fit it here

Question

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is
55%
salt and Solution B is
80%
salt. She wants to obtain
90
ounces of a mixture that is
65%
salt. How many ounces of each solution should she use?

Answer 1

Let the amount (in ounces) of solution A be a and that of solution B be b. You can write the following equations:

.55a + .80b = 90(.65) or .55a + .80b = 58.5

a + b = 90

 

By method of elimination or substitution, you can solve for a and b

a + b = 90 or a = 90 - b

.55(90 -b) + .80b = 58.5

49.5 -.55b + .80b = 58.5

.25b =  9

b = 36

a = 90 - 36 = 54

 

Answer: 54 ounces of Solution A and 36 ounces of Solution B are required to make 90 ounces of a 65% salt solution

 

Check work: .55(54) + .80(36) = 58.5