If two different solutions of alcohol with a respective proportion of water to alcohol of 3:1 and 2:3 were combined, what is the concentration of alcohol in the new solution if the original solutions were mixed in equal amounts?
Select the correct option.
A) 30.0 %  B) 36.6 %  C) 42.5 %  D) 44.4 %  E) 60.0 %

Rationale: alcohol : water first mixture - - 3 : 1 - - 15 : 5 second mixture - - 2 : 3 - - 8 : 12 equal amounts of the mixture were combined , hence the final mixture will be in the ratio - - ( 15 + 8 ) : ( 5 + 12 ) - - 23 : 17 % of alcohol - - 17 / ( 23 + 17 ) * 100 = ( 17 / 40 ) * 100 = 42.5 answer : c
Answer: C