WEBVTT

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Here is the problem: Independent events have P(A) equals 0.5 and P(B) equals 1 over 3. Find P(A and B) and P(A or B).

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Two independent events A and B.

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Both: multiply, because the events are independent.

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At least one: add and subtract the overlap.

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Exactly one of them.

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Neither.

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So the answer is P(A and B) equals 1 over 6 approximately 0.16666667; P(A or B) equals 2 over 3 approximately 0.66666667; P(neither) equals 1 over 3 approximately 0.33333333.

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For independent events the probability that both happen is the product of the individual probabilities.

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P(A or B) plus P(neither) equals 1 equals 1.