Check sibling questions

If A and B are two events such that P(A) = 0.2 , P(B) = 0.4 and P(A ∪ B) = 0.5 , then value of P(A|B) is ?

(a) 0.1             (b) 0.25             (c) 0.5             (d) 0.08


Transcript

Question 4 If A and B are two events such that P(A) = 0.2 , P(B) = 0.4 and P(A ∪ B) = 0.5 , then value of P(A|B) is ? (a) 0.1 (b) 0.25 (c) 0.5 (d) 0.08 We know that P(A|B) = (𝑃(𝐴" ∩ " 𝐵))/(𝑃(𝐵)) Finding P (A ∩ B) Now, P(A ∪ B) = P(A) + P(B) – P(A ∩ B) 0.5 = 0.2 + 0.4 – P(A ∩ B) 0.5 = 0.6 – P(A ∩ B) P(A ∩ B) = 0.6 – 0.5 P(A ∩ B) = 0.1 Now, P(A|B) = (𝑃(𝐴" ∩ " 𝐵))/(𝑃(𝐵)) = 0.1/0.4 = 1/4 = 0.25 So, correct answer is (c) 0.25 1 mark

  1. Class 12
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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo