Task: Question Answering
Input (English): Problem: a can do a piece of work in 80 days. he works at it for 10 days & then b alone finishes the remaining work in 42 days. in how much time will a and b, working together, finish the work ?
Options: a. 30 days, b. 20 days, c. 25 days, d. 35 days, e. 45 days
Output (English): a