Question

In a boarding house of 80 boys, there are food provisions for 30 days. If 20 more boys join the boarding house, how long will the provisions last ?

Answer 1

Let the provisions last for ‘y' days if 20 more boys join.

Here, this is a case of inverse proportion

More the number of boys, the lesser will be the number of days that the provisions will last

So here, the product of the number of boys and the number of days will be constant.

So, $80\times 30=(80+20)\times y$

$\Rightarrow y=\frac{80\times 30}{100}=24$

Thus, the provisions will last for 24 days