Civil Services TNPSC Group 1 (New Syllabus) Mock Test 2025 Quantitative Aptitude Time and Work Pipe and Cistern
A cistern has two taps which fill it in 12 minutes and 15 minutes respectively. There is also a waste pipe in the cistern. When all the pipes are open, the empty cistern is full in twenty minutes. How long will the waste pipe take to empty a full cistern?
1
8 minutes
2
12 minutes
3
15 minutes
4
10 minutes
5
Answer not known