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If andP(A)=611,P(B)=511and P(A∪B)=711 find (i) P(A ∩ B) (ii) P(A|B) (iii) P(B|A)

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Question

If `P(A) = 6/11, P(B) = 5/11 "and"  P(A ∪ B) = 7/11` find

  1. P(A ∩ B)
  2. P(A|B)
  3. P(B|A)
Sum
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Solution

(i) Now, P(A) + P(B) - P(A ∩ B)= `7/11`

⇒ P(A ∩ B) = `6/11 + 5/11 - 7/11`

`= 4/11`

(ii) `P(A|B) = (P(A ∩ B))/(P(B))`

`= (4/11)/(5/11)`

`= 4/5`

(iii) `P (B|A) = (P(A ∩ B))/(P (A))`

`= (4/11)/(6/11)`

`= 4/6`

`= 2/3`

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Chapter 13: Probability - Exercise 13.1 [Page 538]

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NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 13 Probability
Exercise 13.1 | Q 5 | Page 538

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