Question

15 post cards cost Rs 2.25 what will be the cost of 36 Post cards​

Answer 1

$price \: of \: 15 \: cards = 2.25$

$price \: of \: 1\: cards = \frac{2.25}{15}$

$price \: of \: 36 \: cards = \frac{2.25}{15} \times 36 \\ = 5.4$