Required Mathematical Intelligence

Chapter 12 The Busy Pigeon

My brother went for a field trip in the countryside on foot in the morning.After walking for an hour, my younger brother learned from TV that it was raining at noon, so he immediately sent an umbrella to his elder brother by bicycle.When going out, a little pigeon raised by the two brothers flew out at the same time.It flew over the elder brother's head and immediately turned around and flew towards the younger brother, and then turned around and flew towards the older brother when it reached the younger brother's head, until the younger brother caught up with the older brother.It is known that the walking speed of the elder brother is 1 kilometers per hour, the speed of the younger brother riding a bicycle is 4 kilometers per hour, and the speed of the pigeon is 20 kilometers per hour. If the time for the pigeon to turn around is not counted, when the younger brother catches up with the older brother, how much does the pigeon fly in total? kilometer?
[Answer: If you want to find the distance that the pigeon flies each time, it will complicate the problem, because the positions of the two brothers are changing from time to time, and the distance between them is also constantly changing (shrinking), it is difficult for you Find the result.In fact, this problem is not complicated, because pigeons fly continuously, and the flight distance can be calculated only by calculating the flight time. This time is the time when the younger brother catches up with the older brother by bicycle, which is easy to find.Answer: 25 kilometers. ]
(End of this chapter)