Answer:
20 miles per hour
Step-by-step explanation:
Given that the train left for London, and after 9 hours later, a car traveling 80 miles per hour tried catching up to the train. After 3 hours, the car caught up
Which means that the car travelled the same distance in 3 hours as the train travelled in 9 + 3 = 12 hours
Let the distance be d
Given the speed of car is 80 miles per hour
We know that [tex]speed=\frac{distance }{time}[/tex]
[tex]80=\frac{d}{3}[/tex]
d = 240 miles
Now for the train Average speed = total distance / total time taken
Average speed of the train = [tex]\frac{240}{12}[/tex] = 20 miles per hour
