Correct answer to Floor 1 ("Four Seasons"). The key to this question is: time consistency, that is, the time it takes for the dog to run and the time it takes for the brother to catch up with the brother are the same. The formula is: s=Z(MX)/(Y-X), where (M*X)/(Y-X) is the time for the dog to run.
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The time a dog runs is the same as the time a human runs
(5x10/(15-10))x20 = 200
Correct answer to Floor 1 ("Four Seasons"). The key to this question is: time consistency, that is, the time it takes for the dog to run and the time it takes for the brother to catch up with the brother are the same. The formula is: s=Z(MX)/(Y-X), where (M*X)/(Y-X) is the time for the dog to run.