A scientist has two solutions, which she has labeled Solution A and Solution B.

Question

Each solution contains salt. She knows that Solution A is 60% salt and Solution B is 80% salt. She wants to obtain 40 ounces of a mixture that is 65% salt. How many ounce of each should she use?

Answer 1

,8x + .6(40-x) = .65(40)

.8x -.6x = .65(40) -.6(40)

.2x = .05(40) = 2

x = 2/.2= 10 ounces of 80%

40-x = 30 ounces of 60%

60 is within 5 of 65

80 is within 15 of 65

15/5 = 3 times as much 60% as 80%

30=3 times 10

60% of 30 = 18

80% of 10 = 8

8+18 = 26

65% of 40 = 26