During a clearance sale, the price of a cell phone was reduced by 25%. Jonathon purchased the cell phone and, after an 8% sales tax, paid a total of $178.20. What was the original price of the cell phone?

Hey there!

Your answer is $220.

First off, let's make sure we understand that the sales tax is applied after the 25% discount has been applied.

So, the price he paid was 108% of the discounted price: 100% plus the 8% sales tax.

108% in decimal form is 1.08 (move the decimal 2 places to the left).

To get the final price after tax from the price before tax, you would multiply the price before tax by 1.08, so we'll do the opposite and divide the final price by 1.08.

178.20 ÷ 1.08 = 165

The discounted price is $165.  

This is 75% of the original price, which is 0.75. Just like the last step, we are going to divide by this to get the original price of the phone.

165 ÷ 0.75 = 220

The original price of the cell phone is $220.

Hope this helps!

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6