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?

2 Answers
May 11, 2018

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

May 12, 2018

#$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#