Georgia participated in a sleep study in which scientists found that she fell into REM sleep exactly every 45 minutes while she was asleep. If Georgia was asleep for 6One-half hours (390 minutes), how many periods of REM sleep did she have?

Question

A number line going from 0 to 420 in increments of 30.
6 periods
7 periods
8 periods
9 periods

Answer 1

To determine how many periods of REM sleep Georgia had during her sleep, we need to find out how many 45-minute intervals fit into the total sleep time of 390 minutes.

1. Convert her total sleep time into intervals of 45 minutes:

   \[ \text{Number of 45-minute intervals} = \frac{\text{Total sleep time}}{\text{Interval length}} = \frac{390 \text{ minutes}}{45 \text{ minutes}} \]

2. Performing the division:

   \[ \frac{390}{45} = 8.66667 \]

This result means that Georgia experienced 8 full periods of REM sleep, rounding down because you can't have a fraction of a period.

Thus, the total number of periods of REM sleep Georgia had is 8 periods.