Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2005 · Marks: · Difficulty:
It is required to fix a pipe such that water flowing through it at a speed of 7 metres per minute fills a tank of capacity 440 cubic metres in 10 minutes. The inner radius of the pipe should be
(a)$\sqrt{2} \mathrm{m}$
(b)2 m
(c)$\frac{1}{2} \mathrm{m}$
(d)$\frac{1}{\sqrt{2}} \mathrm{m}$
Answer
Answer (as printed): A
Explanation
Let the inner radius of the pipe be $r$ metres. Then, Volume of water flowing through the pipe in 10 min $$\begin{aligned} & =\left[\left(\frac{22}{7} \times r^{2} \times 7\right) \times 10\right] \mathrm{m}^{3}=\left(220 r^{2}\right) \mathrm{m}^{3} . \\ & \therefore 220 r^{2}=440 \Rightarrow r^{2}=2 \Rightarrow r=\sqrt{2} \mathrm{m} . \end{aligned}$$