Correct Answer - Option 3 : Rs. 40,000

**Given:**

The cost price(C.P) of the laptop is Rs. 24,000.

The retailer gave a 25% discount on the marked price(M.P).

The laptop is sold at 25% profit.

**Concepts used:**

M.P. = S.P.(Selling price) + Discount

Discount % = Discount/M.P. × 100

Profit % = {(S.P. – C.P.)/C.P.} × 100

**Calculation:**

C.P. of laptop = Rs. 24,000

Let M.P. of laptop be Rs. x.

Discount % = 25

⇒ {(x – S.P.)/x} × 100 = 25

⇒ S.P. = 3x/4

Profit % = 25

⇒ {(3x/4 – C.P.)/C.P} × 100 = 25

⇒ C.P. = 3x/5

⇒ 3x/5 = Rs. 24,000

⇒ x = Rs. 40,000

**∴**** Marked price of laptop is Rs. 40,000.**