WEBVTT

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Here is the problem: An event has 5 favorable outcomes out of 20 equally likely outcomes. What is its probability?

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Single event (favorable divided by total).

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Divide favorable outcomes by total equally likely outcomes.

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Complement: the event does not happen.

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Odds in favor.

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So the answer is P(A) equals 1 over 4 approximately 0.25 (25 percent).

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The event occurs in 5 of 20 equally likely outcomes, so its probability is 25 percent; it fails with probability 75 percent.