outlet of the top basin fills the lower basin in two hours, the second in three hours, and the third in four hours. When all three upper outlets are shut, the first outlet of the lower basin empties it in three hours, the second in four hours, and the third in five hours.If all the outlets are opened, how long will it take for the lower basin to fill? 2. This problem is also from the work of Piero della Francesca (1415-1492). Of three workmen, the second and third can complete a job in 10 days. The first and third can do it in 12 days, while the first and second can do it in 15 days. In how many days can each of them do the job alone?

Fig: 1

Fig: 2