Task: Question Answering
Input (English): Problem: a can finish a piece of work in 5 days . b can do it in 15 days . they work together for two days and then a goes away . in how many days will b finish the work ? 
Options: a ) 3 days , b ) 5 days , c ) 4 days , d ) 6 days , e ) 7 days
Output (English): e