Task: Question Answering
Input (English): Problem: two pipes p and q can fill a cistern in 12 and 15 minutes respectively . both are opened together , but at the end of 2 minutes the first is turned off . how many more minutes will it take for the cistern to fill after the first pipe is turned off ? 
Options: a ) 8.5 , b ) 9.5 , c ) 10.5 , d ) 11.5 , e ) 12.5
Output (English): c