Question 981902: car A and car B start together. Car A travels once around the circular track at 30 mph. car b travels in the opposite direction at 20 mph, until he passes car A. From this point, at what speed must car B travel to finish once around the track at the same time that car A does?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! car A and car B start together. Car A travels once around the circular track at 30 mph.
car b travels in the opposite direction at 20 mph, until he passes car A.
From this point, at what speed must car B travel to finish once around the track at the same time that car A does?
:
Assume the distance around the track is 100 mi, not realistic, but convenient
Let t = travel time for them to meet
30t + 20t = 100
50t = 100
t = 100/50
t = 2 hrs for them to meet (sorry about this screw-up)
:
Find how far each traveled when they met
2*30 = 60 mi by car A
2*20 = 40 mi by car B
:
Find how long it will take Car A to travel the last 40 mi
40/30 = 1.3333 hrs
:
Find how fast Car B has to go to cover his last 60 mi in 1.333 hrs
60/1.333 = 45 mph for Car B to arrive at the starting point as the same time car A arrives
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