Question
Mathematics Question on Mensuration
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 three are opened, the empty cistern is full in 20 minutes. How long will the waste pipe take to empty the full cistern?
A
5 minutes
B
10 minutes
C
15 minutes
D
20 minutes
Answer
10 minutes
Explanation
Solution
The correct option is (B): 10 minutes