How much water must be evaporated from 16 ounces of 3% salt solution to make 4% salt​ solution?

Answer 1

let the amount of water to be evaporated be x ounces

0.03(16) = 0.04(16-x)
times 100
3(16) = 4(16-x)
48 = 64 - 4x
4x = 16
x = 4