A piece of land was sold to a person through two middlemen, each gaining $25\%$. If the person purchased the land for $₹6,25,000$, the original cost (in ₹) of the land was:

Let the original cost of the land be $C$.The land passes through two middlemen, each adding a gain of $25\%$.$25\%$ as a fraction is $\frac{25}{100}=\frac{1}{4}$. The selling factor for each middleman is $\left(1+\frac{1}{4}\right)=\frac{5}{4}$.So, the final purchase price is:
$$C\times \frac{5}{4}\times \frac{5}{4}=6,25,000$$
$$C\times \frac{25}{16}=6,25,000$$
$$C=6,25,000\times \frac{16}{25}$$
Since $625/25=25$:
$$C=25,000\times 16=4,00,000$$
Thus, the original cost of the land was $₹4,00,000$.