other govt exam India Post Postman & Mail Guard Mock Test 2020 Quantitative Aptitude Time and Work Pipe and Cistern
Pipe A and B can fill a tank in 20 hrs and 15 hrs respectively. Pipe C can empty the full tank in 6 hrs. If all three pipes opened together, then in how many hours the tank will get empty?
1
40 hrs
2
20 hrs
3
10 hrs
4
25 hrs