Jen had some money. She spent 25% on rent and 10% of her remaining money on a skirt. She had $378 left.

1. How much did she have at first?
2. If the skirt was bought at a 40% discount, what was the original price of the skirt?

(a)
Percent of Jen's amount left after she spent on rent
= 100% - 25%
= 75%

Percent of Jen's remaining amount left after she spent on the skirt
= 100% - 10%
= 90%

Fraction of Jen's amount left
= 90% x 75% 
= ⁹⁰₁₀₀ x ⁷⁵₁₀₀
= ²⁷₄₀

Total amount that Jen had = 40 u
Amount that Jen had left = 27 u

27 u = 378

1 u = 378 ÷ 27 = 14

Amount that Jen had at first
= 40 u
= 40 x 14
= $560

(b)
Fraction of Jen's amount spent on the skirt
= 10% x 75% 
= ¹⁰₁₀₀ x ⁷⁵₁₀₀ 
= ³₄₀

Amount that Jen spent on the skirt
= 3 u
= 3 x 14
= $42

Discounted price of the skirt in percent
= 100% - 40%
= 60%

60% of the price of the skirt = 42
1% of the price of the skirt = 42 ÷ 60 = 0.7
100% of the price of the skirt = 100 x 0.7 = 70

Original price of the skirt = $70

Answer(s): (a) $560; (b) $70