Task: Question Answering
Input (English): Problem: tom , working alone , can paint a room in 16 hours . peter and john , working independently , can paint the same room in 8 hours and 4 hours , respectively . tom starts painting the room and works on his own for two hour . he is then joined by peter and they work together for two hour . finally , john joins them and the three of them work together to finish the room , each one working at his respective rate . what fraction of the whole job was done by peter ? 
Options: a ) 4 / 7 , b ) 5 / 7 , c ) 2 / 7 , d ) 1 / 7 , e ) 3 / 7
Output (English): e