Task: Question Answering
Input (English): Problem: a can do a half of certain work in 70 days and b one third of the same in 35 days . they together will do the whole work in ? 
Options: a ) 1 / 65 , b ) 1 / 62 , c ) 1 / 63 , d ) 1 / 60 , e ) 1 / 61
Output (English): d