other govt exam India Post Postman & Mail Guard Mock Test 2020 Quantitative Aptitude Time and Work Pipe and Cistern
Two pipes A and B can fill a cistern in 9 minutes and 6 minutes respectively. Both the pipes are turned on simultaneously. When should the second pipe be closed, if the cistern is to be filled in 4 minutes?
1
13/6 min
2
10/3 min
3
15/4 min
4
7/2 min