Price before DiscountDate: 6/3/96 at 18:16:4 From: George Dickenson Subject: The price of a calculator A calculator is discounted 20 percent. After adding 7 percent tax, the total cost is $20.07. What was the list price of the calculator, without tax, before discount? Date: 6/14/96 at 0:56:23 From: Doctor Brian Subject: Re: math problems When 20 percent is discounted from a price, you still have to pay 80 percent of the original price. When 7 percent tax is added to a price, you have to pay that plus 100 percent of what you normally would, for a total of 107 percent of the actual price. We'll use these two ideas in the problem. If x is the original price, then we are paying 107 percent of (the sale price), which is 107 percent of (80 percent of the original price). And since the word "of" means "times" in percent problems, we get 1.07 * .80 * x = 20.07 .856 * x = 20.07 x = 23.45 -Doctor Brian, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/dr.math/