Question

Shawnee bought a shirt on sale that was 20% off of the original price. The original price was $5 more than the sale price. What was the original price? Use a model and check your work using the 80/20 rule.

Answer 1

Let's assume that x is the sale price of the shirt.

If the sale price is 20% off the original price, then the original price would be:

x + 0.2x = 1.2x

We also know that the original price was $5 more than the sale price, so:

1.2x = x + 5

Solving for x, we get:

0.2x = 5

x = 25

Therefore, the sale price of the shirt was $25.

To check our work using the 80/20 rule, we can find 20% of the original price:

20% of x = 0.2 * (x + 5) = 0.2x + 1

We can see that 20% of the original price is $5 more than the sale price of $25.

0.2x + 1 = 25 + 5

0.2x = 29

x = 145

Therefore, the original price of the shirt was $145.

To check this answer, we can find the sale price by taking 80% of the original price:

80% of 145 = 0.8 * 145 = 116

We can see that the sale price of $25 is indeed $5 less than the original price of $116.

So our answer checks out!