SOLUTION: Events A and B are dependent and disjointed. It is known that one of the events A and B must occur. The probabilities of events A and B are p and p^2. Find p.
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-> SOLUTION: Events A and B are dependent and disjointed. It is known that one of the events A and B must occur. The probabilities of events A and B are p and p^2. Find p.
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Question 1198789: Events A and B are dependent and disjointed. It is known that one of the events A and B must occur. The probabilities of events A and B are p and p^2. Find p. Answer by ikleyn(52803) (Show Source):
From the problem, p^2 + p = 1, or
p^2 + p - 1 = 0.
Then the quadratic formula gives
= = .
It provides one positive and one negative root.
We choose the positive value
p = = 0.618 (rounded). ANSWER
