Task: Question Answering
Input (English): Problem: working alone, mary can pave a driveway in 4 hours and hillary can pave the same driveway in 3 hours. when they work together, mary thrives on teamwork so her rate increases by 33.33 %, but hillary becomes distracted and her rate decreases by 50 %. if they both work together, how many hours will it take to pave the driveway ?
Options: a. 2 hours, b. 4 hours, c. 5 hours, d. 6 hours, e. 7 hours
Output (English): a