The proportion of water to alcohol in Solution A is 4:1 and the proportion of water to alcohol in Solution B is 2:3. If an equal amount of each solution is mixed together, what is the concentration of alcohol in the new solution?  Pick one
A) 39%
B) 40%
C) 41%
D) 42%
E) 43%
Let V be the total volume of the new solution.   Then a volume of V/2 was added from each solution A and B.   The amount of alcohol added to the new solution was:   (1/5)(V/2)+(3/5)(V/2)=V/10+3V/10=4V/10=2V/5.   The concentration of alcohol is 2/5=40%   The answer is 40%.
<result>B</result>
The proportion of water to alcohol in Solution A is 4:1 and the proportion of water to alcohol in Solution B is 2:3. If an equal amount of each solution is mixed together, what is the concentration of alcohol in the new solution?