Comprehension Passage
Direction: A swimming pool is fitted with three pipes P. Q and R. P and Q together can fill the pool in 12 hours. Q and R can together fill it in 20 hours. P and R together can fill it in 10 hours. All the pipes have uniform rate of flow.
If pipes Q and R, instead of filling the pool, start sucking water from it at the same rate and all pipes are open, then in how much time the empty pool can be fully filled (in hours)?
1
12
2
48
3
60
4
72
5
Pool can never be fully filled