Question

Lacey has a 20% off coupon for Bed Bath and Beyond. She wants to buy a set of glasses priced at $24. If she uses her coupon, what is the cost of the glasses before tax?

Answer 1

`$24 \times (1 - 20/100) = 24 \times .8 = $19.20`

Answer 2

`$19.20`

Explanation:

`20%` off `$24` is the same as saying `100% - 20% = 80%` of the original price.

So what is `80%` of `24`?

Let's turn it into an equation, but here are a couple things to remember:

1. Use a variable for what you're solving. I'm going to give the thing we don't know the variable `x`.
2. The word "is" means "equals", so wherever you see that word, you can use an `=` sign.
3. The word "of" means "times", so you can use a `xx` sign for that word.
4. `80%` is the same thing as `80/100 rarr 8/10` as a fraction or `0.8` as a decimal. I will be using the fraction form in the equation.

`stackrel(x)overbrace"What" stackrel(=)overbrace"is"stackrel(8/10)overbrace(80%) stackrel(xx)overbrace"of"stackrel(24)overbrace"24"`

`x = 8/10 xx 24`

`x = (8 xx 24)/10`

`x = 192/10`

`x = 19.2`

So Lacey paid `$19.20`