Which of the following successive discounts is better for a customer?
a. 20%,15%,10%
b. 25%,12.5%,10%

Correct option is B

Given:
Option a: 20%, 15%, 10% successive discounts
Option b: 25%, 12.5%, 10% successive discounts
Formula Used:
Final Price Multiplier = $$(1 - \frac{d_1}{100})(1 - \frac{d_2}{100})(1 - \frac{d_3}{100})$$​​
Solution:
Assume the Marked Price is 100 to compare the final selling prices directly. The lower selling price is better for the customer.
Selling Price for Option a:
SP(a) = 100 × 0.80 × 0.85 × 0.90 = 61.2 (which signifies an effective discount of 38.8%)
Selling Price for Option b:
SP(b) = 100 × 0.75 × 0.875 × 0.90 = 59.0625 (which signifies an effective discount of 40.9375%)
Since Option b yields a lower selling price (or higher effective discount), it is better for the customer.
Final Answer
So the correct answer is (b)