Two 12-Hour Periods The 12-hour system divides the 24 hours of a day into two periods lasting 12 hours each. The first 12-hour period is designated as am. It runs from midnight to noon. The second period, marked pm, covers the 12 hours from noon to midnight.
Step-by-step explanation: You know that at a rate of 52 miles per hour on a highway. Aunt is 390 miles away. Divide 390 by 52 and you get 7.5. So it will take Ms. Wilson 7.5(7hr 30 min) to see her beloved aunt.