Conversion Factors.
1 cup = 8 fluid ounces.
4 cups = 1 quart
4 quarts = 1 gallon
Solution
Use a method call unit fractions. It is simple to use. All you do is arrange the fraction so that 1 part of the unit fraction on the right cancels with 1 part of the fraction on its left. Then divide the numerator by the denominator when each has been multiplied. All this will become clearer if you follow the example below.
[tex]\text{5 gallons} * \dfrac{4 quarts}{1 gal}*\dfrac{4 cups}{1 quart}*\dfrac{8 oz}{1 cup}*\dfrac{1 glass}{4oz}[/tex]
numerator: 5 * 4 * 4 * 8 * 1 = 640
denominator: 1 * 1 * 1 * 1 * 4 = 4
Answer: numerator/ denominator = 640/4 = 160 glasses / 5 gallons.
