Task: Question Answering
Input (English): Problem: mixture a is 15 percent alcohol , and mixture b is 50 percent alcohol . if the two are poured together to create a 4 - gallon mixture that contains 30 percent alcohol , approximately how many gallons of mixture a are in the mixture ? 
Options: a ) 1.5 , b ) 1.7 , c ) 2.3 , d ) 2.5 , e ) 3.0
Output (English): c