Two cars, 100 kilometers apart, start driving toward each other. The black car drives west at a speed of forty kilometers per hour and the white car at a speed of sixty kilometers per hour. A bird starts from the same spot as the white car and flies at a speed of 80 kilometers per hour. When the bird reaches the black car, it turns and flies back toward the white car, whereupon it turns and flies back again to the black car. This continues until the cars meet.
How far has the bird traveled at the moment when the two cars pass each other?
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The Answer:
If you have written down a full paper of mathematical formulas, you haven't been thinking in the right direction. It is obvious that the two cars meet each other after one hour. At that moment, the bird, flying 80 kilometers per hour, has flown for one hour.
If the bird is flying at 80 kilometers per hour for 1 hour, then it has traveled 80 kilometers.
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