defence exam Agniveer Army Tradesman Mock Test Series 2025 Quantitative Aptitude Time and Work Pipe and Cistern
A cistern is provided with two pipes A and B. A can fill it in 20 minutes and B can empty it in 30 minutes. If A and B be kept open alternately for one minute each, how soon will the cistern be filled?
1
110 minutes
2
115 minutes
3
120 minutes
4
121 minutes