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If a and B Are Two Events Associated with a Random Experiment Such that P(A) = 0.5, P(B) = 0.3 and P (A ∩ B) = 0.2, Find P (A ∪ B).

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Question

If A and B are two events associated with a random experiment such that
P(A) = 0.5, P(B) = 0.3 and P (A ∩ B) = 0.2, find P (A ∪ B).

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Solution

Given:
P(A) = 0.5, P (B) = 0.3 and P (A ∩ B) = 0.2
By addition theorem, we have:
P (A ∪ B) = P(A) + P (B)  - P (A ∩ B)
⇒ P (A ∪ B) = 0.5 + 0.3  - 0.2
                     =  0.8 - 0.2 = 0.6
Hence, P (A ∪ B) = 0.6

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Concept of Probability - Probability of 'Not', 'And' and 'Or' Events
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Chapter 33: Probability - Exercise 33.4 [Page 68]

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R.D. Sharma Mathematics [English] Class 11
Chapter 33 Probability
Exercise 33.4 | Q 3 | Page 68

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