Answer:
Marc didn't make it in time for dinner
Explanation:
Marc left home 12:00 p.m, and his dinner was ready 6:00 p.m (18:00), he needed;
18:00 - 12:00 = <u><em>6 hrs</em></u>
Marc needed to spend at most 6 hours on the road in order to get to his mom's house early.
The unit mph means "miles per hour"
The formula to be used here is
speed (in mph) = distance (in miles) ÷ time (in hours)
The speed and distance are 45 mph and 300 miles respectively (as provided in the question). The time spent on the road is unknown.
Hence,
45 mph = 300 miles ÷ time
time = 300 ÷ 45
time = 6.67 hours
In order to get the actual time (in hours and minutes) spent on the road, the ".67" in the answer above will have to be converted to minutes because the clock is not represented in decimal places.
After the decimal, 100 will represent 60 minutes hence,
100 ⇒ 60 mins
67 ⇒ x mins
x = (60 × 67) ÷ 100
x = 40.2 mins
Hence, it must have taken Marc 6 hours and 40 minutes to get to his mom's house, meaning he arrived his mom's house at 18:40 (6:40 p.m). This means Marc arrived late for his dinner.