Question

The sale price on a TV is 30% off the regular price. If the regular price is $420, how much will you save and what is the final cost after 8% sales tax?

Answer 1

You will save $126
The final price will be $317.52

Explanation:

To solve this problem first we need to take the numbers out of the word problem

So we have base price: `$420`
Discount: `30% of $420`
Tax: `8% of $420`

We then simplify all the percents into actual dollar values (I'm assuming you know `100%=1` for these calculations)
`.3*420=126` is your discount

So our new price is
`420-126=294`

Next we find the tax
`.08*294=23.52`

So our new price is
`294+23.52=317.52`

This is our final price

The formula for this is
`(%tax+100%)(basePrice-basePrice*%discount)`

In this case
`(8%+100%)($420-420*30%)`