A pipe can fill a tank in $12$ hours while another empties it in $18$ hours. If both are opened together, the tank will fill in:
Practice this question from Chapter Mock 7: Time and Work, Pipe and Cistern, with options and an explanation.
Question
A pipe can fill a tank in $12$ hours while another empties it in $18$ hours. If both are opened together, the tank will fill in:
Option A
24 hours
Option B
30 hours
Option C — Correct answer
36 hours
Correct choice.
Option D
54 hours
Explanation
Net rate $=\frac1{12}-\frac1{18}=\frac1{36}$. Time $=36$ hours.