Question

A laboratory technician needs to make a 40​-liter batch of a 40​% acid solution. How can the laboratory technician combine a batch of an acid solution that is pure acid with another that is 20​% to get the desired​ concentration?

Answer 1

not sure how to explain
40*0.40=0.2(40-x)+1x
16=8-0.2x+x
minus 8 both sides
8=0.8x
divide both sides by 0.8
10=x
40-10=30

10liters of the pure and 30 liters of the 20%