Task: Question Answering
Input (English): Problem: it takes avery 3 hours to build a brick wall while tom can do it in 3 hours. if the two start working together and after an hour avery leaves, how much time will it take tom to complete the wall on his own ?
Options: a. 20, b. 60, c. 30, d. 40, e. 50
Output (English): b