railway RRB NTPC Mock Test Series 2024-25 (CBT 1 + CBT 2) Quantitative Aptitude Time and Work Pipe and Cistern
An inlet pipe fills up a cistern in 2 hours, while an outlet pipe empties it in 4 hours. The empty cistern was being filled up with both the pipes open for 1 hour, after which someone closed the outlet. How long will it take in total to fill up the cistern?
1
2 hours 15 minutes
2
2 hours 30 minutes
3
3 hours
4
1 hour 30 minutes