PSLE
Yen wanted to buy a shirt. She saw a red shirt on sale at 10% discount and a brown shirt at 20% discount. Both shirts had the same original price before the discounts. To buy the red shirt, Yen would need $4.10 more that what she had. So Yen bought the brown shirt. After that, she had $11 left.

1. What was the original price of the red shirt?
2. How much money did Yen have at first?

	Red shirt	Brown shirt
Before	100%	100%
Change	- 10%	- 20%
After	90%	80%

(a)
Difference in the discount between the red shirt and the brown shirt
= 20% - 10%
= 10%

Additional amount that Yen needed to pay if she would buy the red shirt
= 4.10 + 11
= $15.10

10% →  15.10
100% → ^15.10₁₀ x 100 = 151

Original price of the red shirt = $151

(b)
Price of the brown shirt after discount in percentage
= 100% - 20%
= 80%

Price of the brown shirt after discount
= ⁸⁰₁₀₀ x 151
= $120.80

Amount that Yen had at first
= 120.80 + 11
= $131.80

Answer(s): (a) $151; (b) $131.80