Question

A pump can fill a tank with water in $2$ hours. Because of a leak in the tank, it take $\frac{7}{3}$ hours to fill the tank. The leak can empty the filled tank in:

• A. $8$ hours
• B. $7$ hours
• C. $\frac{13}{3}$ hours
• D. $14$ hours

Answer 1

Answer: (D)

$14$ hours

Work done by pump in $1$ hr$=\frac{1}{2}$

But because of leak work done by pump in $1$ hr $\frac{3}{7}$

$\therefore$Work done by leak in $1$ hr=$\frac{1}{2}-\frac{3}{7}=\frac{1}{14}$

Hence the leak can empty the filled tank in $14$ hours.