Task: Question Answering
Input (English): Problem: at 15 : 00 there were 20 students in the computer lab . at 15 : 03 and every three minutes after that , 3 students entered the lab . if at 15 : 10 and every ten minutes after that 9 students left the lab , how many students were in the computer lab at 15 : 44 ? 
Options: a ) 7 , b ) 14 , c ) 25 , d ) 27 , e ) 30
Output (English): c