How many ounces?

Question

How many ounces of a 15% alcohol solution must be mixed with 6 ounces of a 20% alcohol solution to make a

17% alcohol​ solution?

Answer 1

9 ounces

..15x + .20(6) = .17(x+6) = .17x +1.02

.17x - .15x = 1.2 - 1.02

.02x = .18

x = .18/.02 = 18/2 = 9

or

20-17 = 3

17-15 = 2

you need 3/2 times 6 = 9 ounces