Question

Mark (✓) against the correct answer
10 pipes of the same diameter can fill a tank in 24 minutes. If 2 pipes go out of order, how long will the remaining pipe take to fill the tank?

(a) 40 min
(b) 45 min
(c) 30 min
(d) $19\frac{1}{5}$ min

Answer 1

Time taken to fill the tank by 10 pipes = 24 min
Time taken to fill the tank by 1 pipe = 24 $\times$10 min [Less pipes, more time taken]
Time taken to fill the tank by 8 pipes = $\frac{24\times 10}{8}$ min = 30 min [More pipes, less time taken]
Hence, it will take 30 minutes to fill the tank if two pipes go out of order.

The correct option is (c).