Explanation:

To find the single discount equivalent to successive discounts, multiply the complements of the discounts and subtract from 1:

- Start with 100%:

- First, apply the 20% discount:

- 100% - 20% = 80% (or 0.8 in decimal form)

- Second, apply the 35% discount:

- 80% of 100% becomes 65%: $0.8\times (1-0.35)=0.8\times 0.65=0.52$

- Finally, apply the 10% discount:

- 52% becomes 90% of it: $0.52\times (1-0.1)=0.52\times 0.9=0.468$

- The combined effect is a single discount equivalent to 1 - 0.468 = 0.532, or 53.2%

- Therefore, Option 1: 53.2% is the correct answer.