Question

If for two events A and B, P(A – B) = `1/5` and P(A) = `3/5`, then `P(B/A)` is equal to ______.

विकल्प

• `1/2`

• `2/5`

• `3/5`

• `2/3`

Answer 1

If for two events A and B, P(A – B) = `1/5` and P(A) = `3/5`, then `P(B/A)` is equal to `underlinebb(2/3)`.

Explanation:

Given,

P(A – B) = `1/5` and P(A) = `3/5`

∵ P(A – B) = `P(A ∩ overlineB)` 

= P(A) – P(A ∩ B)

`\implies 1/5 = 3/5 - P(A ∩ B)`

`\implies` P(A ∩ B) = `3/5 - 1/5 = 2/5`

Now `P(B/A) = (P(A ∩ B))/(P(A))`

= `(2/5)/(3/5)`

= `2/3`