在香港遇到一個人的概率 15點

The above is a misconception in my opinion.


I believe we should think in the following way:


1) Classify the time required about the question, say in one hour, or one day or one month or one year.


2) It is essential because when the time increases you can be able to meet more persons, then the probability rises.


3) Estimate the number of persons you can meet in one hour, or one day or one month or one year.

4) Divide this number by the local population to obtain the required probability.


You need to work like above because different persons have different probabilities, and not a constant to all local citizens. See, if someone always stay at home without going out, the probability for him meeting an unknown bus driver is basically zero. But if another person travels by bus everyday for work, then such chance is not zero for one day this driver may driver this route and two persons may cross the path. Understand?


Hope I can help you.

1)1÷1÷1104000÷7061200
=1/7795564800000