Question

The provisions available in the godown can feed 800 children for 60 days. If 400 more children arrive, how long will the stock last?

• A. 30 days
• B. 40 days
• C. 20 days
• D. 10 days

Answer 1

The correct option is B 40 days

When the number of children increases, the number of days for which the provisions last will decrease. This is a case of inverse proportion.

$So,\text{Number of children}\left(x\right)\propto \frac{1}{\text{Days}\left(y\right)}$
$\therefore \frac{x_1}{x_2}=\frac{y_2}{y_1}$

Given,
$x_1=800\text{children}$
$y_1=60\text{days}$
$x_2=(800+400)=1200\text{children}$
$\text{and}{y}_2=\text{number of days}$

$\Rightarrow y_2=\frac{x_1\times y_1}{x_2}$

$\Rightarrow y_2=\frac{800\times 60}{1200}=40\text{days}$