Tiffany had some money. She spent 20% on food and 30% of her remaining money on a windbreaker. She had $84 left.

1. How much did she have at first?
2. If the windbreaker was bought at a 10% discount, what was the original price of the windbreaker?

(a)
Percent of Tiffany's amount left after she spent on food
= 100% - 20%
= 80%

Percent of Tiffany's remaining amount left after she spent on the windbreaker
= 100% - 30%
= 70%

Fraction of Tiffany's amount left
= 70% x 80% 
= ⁷⁰₁₀₀ x ⁸⁰₁₀₀
= ¹⁴₂₅

Total amount that Tiffany had = 25 u
Amount that Tiffany had left = 14 u

14 u = 84

1 u = 84 ÷ 14 = 6

Amount that Tiffany had at first
= 25 u
= 25 x 6
= $150

(b)
Fraction of Tiffany's amount spent on the windbreaker
= 30% x 80% 
= ³⁰₁₀₀ x ⁸⁰₁₀₀ 
= ⁶₂₅

Amount that Tiffany spent on the windbreaker
= 6 u
= 6 x 6
= $36

Discounted price of the windbreaker in percent
= 100% - 10%
= 90%

90% of the price of the windbreaker = 36
1% of the price of the windbreaker = 36 ÷ 90 = 0.4
100% of the price of the windbreaker = 100 x 0.4 = 40

Original price of the windbreaker = $40

Answer(s): (a) $150; (b) $40