Civil Services Uttarakhand Combined State Civil/Upper Subordinate Services Examination 2025 Quantitative Aptitude Time and Work Pipe and Cistern
A pipe can fill a tank in 6 hours. Another pipe can empty the filled tank in 30 hours. If both the pipes are opened simultaneously, then the time (in hours) in which the tank will be two-third filled, is:
1
20
2
5
3
10
4
15