Task: Question Answering
Input (English): Problem: at a certain paint store forest green is made by mixing 4 parts blue paint with 3 parts yellow paint . verdant green is made by mixing 4 parts yellow paint with 3 parts blue paint . how many liters of yellow paint must be added to 42 liters of forest green to change it to verdant green ? 
Options: a ) 14 , b ) 12 , c ) 15 , d ) 11 , e ) 10
Output (English): a