Question

Seventy five postcards cost $Rs18.75$.How many postcards can be bought for $Rs25$?

Answer 1

Unitary method:

Number of post cards for $Rs18.75=75$

Number of post cards that can be bought for $1Rs$ $$\begin{gathered} =\frac{75}{18.75} \\ =4 \end{gathered}$$

Number of postcards can be bought for $Rs25$$$\begin{gathered} =4\times 25 \\ =100 \end{gathered}$$

Hence number of postcards can be bought for $Rs25$ is $100$