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

Let x L of solution 1 is used and 2nd solution is (200-x)LAccording to question,30% of x + 50% of (200-x) = 42% of 200L0.3x + 0.5(200-x) = 840.3x - 0.5x + 100= 840.2x = 16x=80Therfore 80L of solution 1 and 120L of solution 2 is mixed.