# A vacuum cleaner uses 5/8 kilowatts per hour. A clothes dryer uses 4 11/16 kilowatts per hour. How many hours can the vacuum run and use the same amount of energy as the clothes dryer does in one hour?

$7 \frac{1}{2}$ hours

#### Explanation:

Vacuum cleaner uses $\frac{5}{8} = \frac{10}{16}$ kilowatt per hour

Clothes dryer uses $4 \frac{11}{16} = \frac{75}{16}$ kilowatt per hour

To see how many hours we can run the vacuum cleaner for using the same amount of energy as the dryer does for one hour, we can divide the vacuum cleaner energy into the dryer energy:

$\frac{\frac{75}{16}}{\frac{10}{16}} = \frac{75}{16} \times \frac{16}{10} = \frac{75}{10} = 7.5$

Jonas can run his vacuum for $7 \frac{1}{2}$ hours using the same amount of energy that the dryer does in one hour.