Correct Answer - Option 3 : Rs. 22,500

**Given:**

The cost price of smartphone is Rs. 15,000.

The retailer gave 20% discount on the marked price.

Phone is sold at 20% profit.

**Concepts used:**

M.P. = S.P. + Discount

Discount % = Discount/M.P. × 100

Profit % = Profits/C.P. × 100

Profits = S.P. – C.P.

**Calculation:**

C.P. of smartphone = Rs. 15,000

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

Discount % = 20

⇒ {(x – S.P.)/x} × 100 = 20

⇒ S.P. = 4x/5

Profit % = 20

⇒ {(4x/5) – 15,000)/15,000} × 100 = 20

⇒ x = Rs. 22,500

**∴**** M.P. of smartphone is Rs. 22,500.**