Solution X is 30% chemical A and 70% chemical B by volume. Solution Y is 40% chemical A and 60% chemical B by volume. If a mixture of X and Y is 36% chemical A, what percent of the mixture is Solution X? Choose the correct choice from the following choices.
A) 30%
B) 35%
C) 40%
D) 45%
E) 50%
The volume of the mixture be X+Y.   0.3X +0.4Y=0.36(X+Y)   X=2Y/3   X/(X+Y)=(2Y/3) / (5Y/3)=2/5=40%.   The answer is 40%.
<result>C</result>
Solution X is 30% chemical A and 70% chemical B by volume. Solution Y is 40% chemical A and 60% chemical B by volume. If a mixture of X and Y is 36% chemical A, what percent of the mixture is Solution X?