Question

Mark (✓) against the correct answer:
6 pipes can fill a tank in 24 minutes. One pipe can fill it in
(a) 4 minutes
(b) 30 minutes
(c) 72 minutes
(d) 144 minutes

Answer 1

(d) 144 minutes

Let one pipe take x min to fill the tank.

No. of pipe	6	1
Time(in min)	24	$x$

Clearly, one pipe will take more time to fill the tank.
So, it is a case of inverse proportion.
$$\begin{gathered} \mathrm{Now},6\times 24=1\times x \\ \Rightarrow x=6\times 24 \\ \Rightarrow x=144 \end{gathered}$$

∴ One pipe can fill the tank in 144 minutes.