The marked price of a radio is Rs 480. The owner allows a discount of 10% and still earns the profit of 8%. If no discount is allowed, find his gain percent?25%12%15%20%

Step 1: Calculate the selling price of the radio after the discount.

The discount on the radio is 10% of the marked price. So, the discount amount is 10/100 * 480 = Rs 48.

The selling price after the discount is the marked price minus the discount amount. So, the selling price is 480 - 48 = Rs 432.

Step 2: Calculate the cost price of the radio.

The owner earns a profit of 8% on the selling price. So, the profit amount is 8/100 * 432 = Rs 34.56.

The cost price is the selling price minus the profit amount. So, the cost price is 432 - 34.56 = Rs 397.44.

Step 3: Calculate the gain percent if no discount is allowed.

If no discount is allowed, the selling price would be the marked price, which is Rs 480.

The gain is the selling price minus the cost price. So, the gain is 480 - 397.44 = Rs 82.56.

The gain percent is the gain divided by the cost price, times 100. So, the gain percent is 82.56/397.44 * 100 = 20.76%.

So, if no discount is allowed, the owner's gain percent would be approximately 21%, which is closest to the option of 20%.