A scientist has two solutions,

Question

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 70%

 salt and Solution B is 95%

salt. She wants to obtain 120

 ounces of a mixture that is 75%

 salt. How many ounces of each solution should she use? 

what solution A in ounces

what solution B in ounces

can u explain step by step

Answer 1

70A + 95B = 75(120)

70A + 95(120-A) = 75(120)

-95A +70A = 75(120) -95(120)

-25A = -20(120)

A = 20(120)/25 = 4(24) = 96 ounces of 70%

B = 120-96 = 24 ounces of 95%

or a less conventional way to solve or check the answers

75-70 = 5

95-75 = 20

20/5 = 4 times as much 70% as 95%

4 = x/(120-x)

480 -4x = x

5x = 480

x = 480/5 = 96 ounces of 70%

120-x = 24 ounces of 95%

.7(96) = .95(24)

= 67.2 + 22.8

= 90

= ,75(120)

= 90