We are given three successive discounts: 20%, 50%, and 10%. We want to find the equivalent single discount.

1. Problem Description

We are given three successive discounts: 20%, 50%, and 10%. We want to find the equivalent single discount.

2. Solution Steps

Let the original price be $P$.

After the first discount of 20%, the price becomes $P_1 = P(1 - 0.20) = 0.8P$.

After the second discount of 50%, the price becomes $P_2 = P_1(1 - 0.50) = 0.8P(0.5) = 0.4P$.

After the third discount of 10%, the price becomes $P_3 = P_2(1 - 0.10) = 0.4P(0.9) = 0.36P$.

The final price is 0.36 times the original price. This means that the total discount is $1 - 0.36 = 0.64$.

Therefore, the equivalent single discount is $0.64 \times 100\% = 64\%$.

3. Final Answer

The equivalent single discount is 64%.

The answer is D) 64%.