Percentage problems consist of three values: the base, the rate or percent, and the percentage or amount. The base is the quantity from which a percentage is taken. In the given equation, $60 is the base, while 30 is the rate or percent. The percentage or amount, which is what this particular example seeks to find, is $18.

Percentage problems are often useful in determining the final price of an item on clearance after a certain price deduction. For example if a dress originally costs $50 and is marked 30 percent off, the equation $50 x 0.30 = $15 lets the shopper know she can expect to pay $15 less than usual for the dress, or $35.

Learn more about Fractions & Percentages