Jeff has a coupon at the Guitar Store for 15% off any purchase of $100 or more.
He wants to buy a used guitar that has a price tag of $220 on it.
Any of those parts may be the unknown value to be found.
To solve problems with percent we use the percent proportion shown in "Proportions and percent".
Percentage problems usually work off of some version of the sentence "(this) is (some percentage) of (that)", which translates to "(this) = (some decimal) × (that)".
You will be given two of the values, or at least enough information that you can figure two of them out.
Then you'll need to pick a variable for the value you don't have, write an equation, and solve for that variable.
The format displayed above, "(this number) is (some percent) of (that number)", always holds true for percents.
The correct percent fraction for the proportion is Jeff has a coupon at the Guitar Store for 15% off any purchase of 0 or more.
Jeff wonders how much money the coupon will take off of the 0 original price Percent problems have three parts: the percent, the base (or whole), and the amount.