Task: Question Answering
Input (English): Problem: a can do a piece of work in 28 days and b alone can do it in 10 days. b works at it for 5 days and then leaves. a alone can finish the remaining work in
Options: a. 5 days, b. 6 days, c. 7.5 days, d. 14 days, e. 9 days
Output (English): d