Question

Marcia buys a dress that is on sale for 15% off it's original price. She uses a store coupon to obtain an additional 10% off the sale price. Marcia pays $91.80 for the dress. What was the original price of the dress?

Answer 1

120$

Explanation:

We must calculate the prices with the application of discounts successively

The last discount he got was 10%, so $ 91.80 equals 90% of the price

We calculate the price before this discount by applying with a simple rule of three

`90 \% \longrightarrow 91.80\\100\% \longrightarrow x\\x=((100)(91.80))/(90)\\ x= 102\$`

She pays $ 102 with a 15% discount, so this value equals 85% of the original price

We calculate the price before this discount by applying with a simple rule of three

`85\% \longrightarrow 102\\100\% \longrightarrow x\\x=((100)(102))/(85)\\ x= 120\$`

Answer 2

15% off the original price
10% off the sale price
Sale price $91.80

First we have to find out the price before 10% discount.
(sale price) divided by (1 - percent of sale price)

91.80/(1 -.10) = $102

So, $102 was the price before the 10% discount. Now we need to do the same with the 15% off so that we can get the original price.

102/(1 - .15) = $120

The original price was $120