Question

Pipes M and N can alone fill and alone empty the tank in 12 hours and 24 hours respectively. There is a leakage at the bottom of tank which can empty the tank in 72 hours. If both pipes opened together, then in how much time tank will filled?
1.  48 hours
2. 30 hours
3. 36 hours
4. 24 hours

Answer 1

Correct Answer - Option 3 : 36 hours

Given:

Pipe M's 1 hour's work = 1/12

Pipe N's 1 hour's work = 1/24

Leakage 1 hour's work = 1/72

Calculation:

⇒ 1/12 - 1/24 - 1/72 = 2/72 = 1/36

∴ If both pipes opened together with leakage, the tank gets filled in 36 hours.

Here M is filling the tank, N is emptying the tank and leak is emptying the tank.