Question

Fifteen post cards cost $Rs.\mathrm{2.25.}$ What will be the cost of $36$ post cards? How many postcards can we buy in $Rs.45$?

Answer 1

Cost of $15$ postcards $=Rs.2.25$

Cost of $1$ postcard $=\frac{\text{Total cost}}{\text{Number of postcard}}=Rs.2.25÷15=Rs.0.15$

Cost of $36$ postcards $=36\times \left(0.15\right)=Rs.5.4$

Number of postcards that can be bought for $Rs.45=\frac{\text{Total rupees}}{\text{Cost of each postcard}}$

$=45÷0.15=300$