other govt exam India Post Postman & Mail Guard Mock Test 2020 Quantitative Aptitude Time and Work Pipe and Cistern
Two pipes X and Y can fill a tank in 60 minutes and 75 minutes respectively. There is also an outlet Z. If all the three pipes are used together, the tank is full in 50 minutes. How much time will be taken by Z to empty the full tank?
1
90 minutes
2
100 minutes
3
50 minutes
4
75 minutes