Prashant bought a laptop at a certain cost, he earns a profit of 20% by selling it. If he had bought it for 10% less than the original price, he would have gained 20% profit by selling it at Rs. 1500 less than the previous price. Find the cost at which he bought the laptop initially. 

Prashant bought a laptop at a certain cost, he earns a profit of 20% by selling it. If he had bought it for 10% less than the original price, he would have gained 20% profit by selling it at Rs. 1500 less than the previous price. Find the cost at which he bought the laptop initially.  Correct Answer Rs. 12,500

Let the initial cost price of laptop = 100x

Then initial selling price = 120% of 100 = 120x

New Cost price = 90% of 100x = 90x

New Selling price = 120% of 90x = 108x

Difference of selling price = 120x - 108x = 12x = Rs. 1500

⇒ x = 125

∴ Initial cost price of laptop = 100x = 125 × 100 = Rs. 12,500