railway RRB NTPC Mock Test Series 2024-25 (CBT 1 + CBT 2) Quantitative Aptitude Time and Work Pipe and Cistern
One pipe can fill a pool in 40 minutes and another pipe can empty a pool in 60 minutes. If both the pipes are opened together, then in how many hours will the empty pool be filled?
1
2 hours
2
2.5 hours
3
3 hours
4
3.5 hours