1/25 + 1/35 = 12/175
175/12 = 14 7/12 days
Ravi can do a piece of work in 25 days while Prakash can do it in 35 days. In how many days will they finish it together?

1: 15 7/9 days
2: 16 17/9 days
3: 15 1/19 days
4: 14 7/12 days
5: 14 7/9 days