In 1 hour, the 1st truck has gone 45 miles.
The 2nd truck gains on it at 15 mph (60 - 45)
45/15 = 3 hours
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That's 3 hours after the car leaves, 4 hours after the truck has left.
A truck leaves going 45 mph. One hour later a car going 60 mph leaves in same direction. How long will it take for the car to catch the truck.
2 answers
6 hours