need help with a math problem

Question

A chemist has 20% and 60% solutions of acid available. How many liters of each solution should be mixed to obtain 200 liters of 22% acid solution?

Answer 1

.6x +.2(200-.x) = .22(200) = 44

.4x = 44-40= 4

x= 4/.4= 10 Liters of 60% mixed with 190 Liters of 20% to get 200 Liters of 22%

22-20 = 2

60-22 = 38

38/2=19 = 190/10