Q35 of 43 Page 15

(ii) P(A) = 0.5, P(B) = 0.4, P(A ∪ B) = 0.8


(i) No, because P(A ∩ B) must be less than or equal to P(A) and P(B),
(ii) we know that

P(A ∪ B) = P(A) + P(B) - P(A ∩ B)

⇒ 0.8 = 0.5 + 0.4 – P(A ∩ B)

P(A ∩ B) = 0.1

It is true since it is less than P(A) and P(B).

Hence, P(A) and P(B) are consistently defined.

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