other govt exam India Post Postman & Mail Guard Mock Test 2020 Quantitative Aptitude Time and Work Pipe and Cistern
A pipe can fill the cistern in 8 hours and another can empty the cistern in 12 hours. How long will it take to fill the cistern if both the taps are opened?
1
12 hours
2
20 hours
3
18 hours
4
24 hours