Question

If 9 dozen bananas cost ₹1,080, then find the cost of 4 boxes of bananas containing 5 dozen each.

Answer 1

Given, the cost of 9 dozen bananas = ₹ 1,080

Also, 4 boxes of bananas containing 5 dozen each will have
$4\times 5=20\text{dozen bananas}$

We know that, if the number of bananas increase, the cost will also increase.

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

Given,
$x_1=9\text{dozen bananas}$
$y_1=₹1080$
$x_2=20\text{dozen bananas}$
$\text{and}{y}_2=\text{cost of 20 dozen bananas}$

$\Rightarrow \frac{9}{1080}=\frac{20}{y_2}$
$\Rightarrow y_2=\frac{20\times 1080}{9}=₹2,400$

Hence, the cost of 4 boxes of bananas containing 5 dozen each is ₹ 2,400.