PSLE
Tina wanted to buy a shirt. She saw a black shirt on sale at 20% discount and a yellow shirt at 30% discount. Both shirts had the same original price before the discounts. To buy the black shirt, Tina would need $7.60 more that what she had. So Tina bought the yellow shirt. After that, she had $15 left.

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

	Black shirt	Yellow shirt
Before	100%	100%
Change	- 20%	- 30%
After	80%	70%

(a)
Difference in the discount between the black shirt and the yellow shirt
= 30% - 20%
= 10%

Additional amount that Tina needed to pay if she would buy the black shirt
= 7.60 + 15
= $22.60

10% →  22.60
100% → ^22.60₁₀ x 100 = 226

Original price of the black shirt = $226

(b)
Price of the yellow shirt after discount in percentage
= 100% - 30%
= 70%

Price of the yellow shirt after discount
= ⁷⁰₁₀₀ x 226
= $158.20

Amount that Tina had at first
= 158.20 + 15
= $173.20

Answer(s): (a) $226; (b) $173.20