Question

A pipe can fill a tank of 100 liter in 2 hours. How many pipes are required to fill a bigger tank of 500 liter in 2 hours at the same rate?

• A. 4
• B. 5
• C. 7
• D. 5

Answer 1

The correct option is B 5

Let number of pipe is represented by $P$ and the capacity of tank is $T$.

As both the tanks need to be filled in 2 hours, when capacity of the tank will be more, more pipes will be required to fill it in a given time

Hence, $P\propto T$
$\Rightarrow P=k\times T$ $\because kisaconstant$
$\Rightarrow 1=k\times 100$ liter
$\Rightarrow k=\frac{1}{100}$

$\Rightarrow \frac{P}{T}=\frac{1}{100}$

We have to find the number of pipe required to fill a tank of 500 l.
$\Rightarrow \frac{P}{T}=k\Rightarrow P=T\times k$ (Multiply by T on both the sides)

Put the values of T and k.
$T=500$ liters, $k=\frac{1}{100}$
$\Rightarrow P=\frac{1}{100}\times 500=5$
Hence, 5 pipes are required.