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Ex 13.1, 3 - If P(A) = 0.8, P(B) = 0.5 and P(B|A) = 0.4 - Ex 13.1

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Ex 13.1, 3 - Chapter 13 Class 12 Probability - Part 2

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Ex 13.1, 3 - Chapter 13 Class 12 Probability - Part 3

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Ex 13.1, 3 If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find (i) P(A ∩ B)P(A) = 0.8 , P(B) = 0.5 & P(B|A) = 0.4 Now, we know that P(B|A) = (𝑃(𝐵 ∩ 𝐴))/(𝑃(𝐴)) 0.4 = (𝑃(𝐴 ∩ 𝐵))/(𝑃(𝐴)) 0.4 = (𝑃(𝐴 ∩ 𝐵))/(0. 8) P(A ∩ B) = 0.4 × 0.8 P(A ∩ B) = 0.32 Ex 13.1, 3 If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find (ii) P(A|B)P(A|B) = (𝑃(𝐴 ∩ 𝐵))/(𝑃(𝐵)) = 0.32/0.5 = 32/50 = 0.64 ∴ P(A|B) = 0.64 Ex 13.1, 3 If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find (iii) P(A ∪ B)P(A ∪ B) = P(A) + P(B) – P(A ∩ B) = 0.8 + 0.5 – 0.32 = 1.3 – 0.32 = 0.98 ∴ P(A ∪ B) = 0.98

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.