After getting two successive discounts, a shirt with a list price of Rs. 150 is available at Rs. 105. If the second discount is 12.5 percent, find the first discount.

The first discount is 20%.

Let the first discount be d; then 150 x (1 - d) x (1 - 0.125) = 105.

150 x (1 - d) x 0.875 = 105.

(1 - d) = 105/131.25 = 0.8.

So d = 0.2, that is 20%.