Question 136775: If a car travels 20 km per hour between two cities. How fast must the car travel to average 40 km per hour for the round trip
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! If a car travels 20 km per hour between two cities. How fast must the car travel to average 40 km per hour for the round trip
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It's a trick question, as it's not possible to average 40 kph after going halfway at half that speed.
If the distance is d, and you travel at speed v, the time is d/20 hours.
To travel roundtrip, that's 2d. 2d/40 is the same amount of time as d/20, so there is zero (0) time left for the return trip.
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