Answer :
Let x L of solution 1 is used
and 2nd solution is (200-x)L
According to question,
30% of x + 50% of (200-x) = 42% of 200L
0.3x + 0.5(200-x) = 84
0.3x - 0.5x + 100= 84
0.2x = 16
x=80
Therfore 80L of solution 1 and 120L of solution 2 is mixed.
and 2nd solution is (200-x)L
According to question,
30% of x + 50% of (200-x) = 42% of 200L
0.3x + 0.5(200-x) = 84
0.3x - 0.5x + 100= 84
0.2x = 16
x=80
Therfore 80L of solution 1 and 120L of solution 2 is mixed.