What amount of a 60% acid solution must be mixed with a 30% solution to produce 300 mL of a 45% solution?

Answer 1

amount of 60% stuff --- x ml
amount of 30% stuff ---- 300 - x

.6x + .3(300-x) = .45(300)
.6x + 90 - .3x = 135
.3x = 45
x = 150

150 ml of the 60% solution and 150 ml of the 30% solution

check
.6(150) + .3(150)
= 90+45
= 135 , as needed