Question

if a school - age student has to wake up for school at 7 am, what time should they go to bed to get the minimum recommended hours of sleep?
national sleep foundation
sleep duration recommendations

options:
9 pm
12 am
10 pm
11 pm

Explanation:

Step1: Identify school - age sleep needs

From the Sleep Duration Recommendations, school - age children (presumably the relevant group here) have a minimum recommended sleep duration. Looking at the chart, the minimum recommended sleep for school - age (let's assume the minimum in the recommended range) is 9 hours (from the 9 - 11 range, taking the minimum of 9).

Step2: Calculate bedtime from wake - up time

The student wakes up at 7 am. To get 9 hours of sleep, we work backwards from 7 am. Subtract 9 hours from 7 am.
7 am minus 9 hours:
First, subtract 7 hours from 7 am to get to 12 am (midnight), then we still need to subtract 2 more hours. 12 am minus 2 hours is 10 pm.

Answer:

10 pm (corresponding to the option "10 pm")