Question

Francis heard that a car stereo system was on sale for 30% off. If the sale price was 57.75, what was the original price of the stereo?

Answer 1

$82.50

Explanation:

82.5 times 0.7 = 57.75

doing 57.75 + 30% wouldn't work, so you have to increase the number (original price) being discounted until you get 57.75

also, the '0.7' is 70% which also means '30% off' because you took 30% away from the original price that was 100%

math calculator saves the day? dont use paper or it would take a long time (unless it was a test or teacher said no)

Answer 2

82.50

We can calculate it with a direct rule of 3. As it has a 30% off, the remaining price is the 70% and we want to know how much 100% is.

We use the formula of the direct rule of 3 to give us
x = 82.5

The original price of the stereo was $82.50!