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Mathematics LibreTexts

5: Basic Concepts of Probability


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Thinking out Loud

 What do we mean if we say that the probability of tossing a coin and seeing a head is about 0.5 (50%, or the odds are 50/50)?

One possible answer: We are claiming that if you toss the coin in question a large number of times then you should see heads appearing about half of the time.

Thinking out loud

What do people mean when they refer to a "100 year" flood?

One possible answer: They are claiming that the likelihood of a flood of that magnitude happening in any given year is 0.01 (1%, or the odds are 1/100).