PSLE
Roshel wanted to buy a shirt. She saw a black shirt on sale at 10% discount and a white shirt at 20% discount. Both shirts had the same original price before the discounts. To buy the black shirt, Roshel would need $6.40 more that what she had. So Roshel bought the white shirt. After that, she had $3 left.

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

	Black shirt	White shirt
Before	100%	100%
Change	- 10%	- 20%
After	90%	80%

(a)
Difference in the discount between the black shirt and the white shirt
= 20% - 10%
= 10%

Additional amount that Roshel needed to pay if she would buy the black shirt
= 6.40 + 3
= $9.40

10% →  9.40
100% → ^9.40₁₀ x 100 = 94

Original price of the black shirt = $94

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

Price of the white shirt after discount
= ⁸⁰₁₀₀ x 94
= $75.20

Amount that Roshel had at first
= 75.20 + 3
= $78.20

Answer(s): (a) $94; (b) $78.20