Task: Question Answering
Input (English): Problem: carl can wash all the windows of his house in 6 hours. his wife maggie can wash all the windows in 6 hours. how many hours will it take for both of them working together to wash all the windows ?
Options: a. 2, b. 2 1 / 4, c. 3, d. 4 1 / 2, e. 5
Output (English): c