Question

Water is flowing at the rate of $5km/hr$ through a pipe of diameter $14cm$ into a rectangular tank which is $50m$ long, $44m$ wide. The time taken (in hours) for the rise in the level of water in the tank to be $7cm$ is

• A. $2$
• B. $1\frac{1}{2}$
• C. $3$
• D. $2\frac{1}{2}$

Answer 1

Answer: (A)

$2$

Water flowed by the pipe in $1h=\pi r^{2}h$

$=\frac{22}{7}\times \frac{7\times 7}{100\times 100}\times 5000m^3=77m^3$

Volume of expected water in the tank $=l\times b\times h=\frac{50\times 44\times 7}{100}=154m^3$

$\therefore$ Required time $=\frac{154}{77}=2hrs$.