Question

A solution containing 30% insecticide is to be mixed with a solution containing 50% insecticide to make 200 L of a solution containing 42% insecticide. How much of the 30% insecticide solution should be used?@ ßαbчღ@nyprincess2001

Answer 1

let x L of 30% insecticide to be mixed with (200-x) L of 50% insecticide to make a 42% 200L insecticide solution
so 0.3*x+0.5*(200-x)=0.42*200
100-(0.2*x)=84
0.2*x=16
x=80 L
hence 80 L of 30% insecticide to be used.