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吉林大学远程教育学院

    >>>>   Unit One
    >>>>   Unit Two
    >>>>   Unit Three
    >>>>   Unit Four
    >>>>   Unit Five
    >>>>   Unit Six
    >>>>   Unit Seven
    >>>>   Unit Eight
    >>>>   Unit Nine
    >>>>   Unit Ten
    >>>>   Unit Eleven
    >>>>   Unit Twelve
    >>>>   Unit Thirteen
    >>>>   Unit Fourteen
    >>>>   Unit Fifteen
    >>>>   Unit Sixteen
    >>>>   Unit Seventeen
    >>>>   Unit Eighteen
    >>>>   Unit Nineteen
    >>>>   Unit Twenty
    >>>>   Unit Twenty-one
    >>>>   Unit Twenty-two
    >>>>   Unit Twenty-three
    >>>>   Unit Twenty-four
    >>>>   Unit Twenty-five
    >>>>   Unit Twenty-six
    >>>>   Unit Twenty-seven
    >>>>   Unit Twenty-eight
    >>>>   Unit Twenty-nine
    >>>>   Unit Thirty

Background Information | Synopsis | Warm-up activity | Text |

Synopsis

The essay is about a mathematical problem concerning probabilities and the reasoning process of how it is solved. The story of a retired railroad engineer who had insomnia is simply a method of making the problem-solving more interesting. There is an example to help make the essay more easily understood.

When both you and your friend wanted to watch an exciting football match but had only one ticket, how did you two make the decision on who should go? Maybe you would take a coin and toss it, while asking your friend to guess which side would turn up. When the coin fell on the ground and the side he had guessed turned up, the ticket would belong to him;otherwise, you would get it.

Why did you two consider it more acceptable to make a decision through a coin toss?

Because a coin has two sides, obverse and reverse. If you throw it up, you will expect to see either the obverse or the reverse. The chance that the obverse appears is equal to the chance that the reverse does. Hence, the probability that you make the right guess and get the ticket is the same as the probability for your friend. So both of you admit that your chance are equal.