Description for Correct answer:
We know that, when a pipe fills \( \Large \frac{1}{m} \)part of a tank in 1 h, then the pipe takes m h to fill the tank.

Here, = \( \Large \frac{1}{m} \) = \( \Large \frac{1}{8} \) = m = 8

Therefore, Required time to fill the tank = 8 h