A sold an article to B at a profit of 25%. B sold it to C at a profit of 15%. The profit made by B is ₹40 less than the profit made by A. What is the cost price (in ₹) of the article for A?

Let the cost price of A = 100C

Profit percentage of A = 25%

Profit of A = $$\frac{25}{100}\times$$100C = 25C

Selling price of A = Cost price of B = 100C + 25C = 125C

Profit percentage of B = 15%

Profit of B = $$\frac{15}{100}\times$$125C = $$\frac{75}{4}$$C

The profit made by B is ₹40 less than the profit made by A.

$$\frac{75}{4}$$C = 25C - 40

25C - $$\frac{75}{4}$$C = 40

$$\frac{25}{4}$$C = 40

C = $$\frac{32}{5}$$

Cost price of the article for A = 100C = $$100\times\frac{32}{5}$$ = ₹640

Hence, the correct answer is Option B