In a school there are 1000 students, out of which 430 are girls. It is known that out of 430, 10% of the girls study in class XII. What is the probability that a student chosen randomly studies in Class XII given that the chosen student is a girl?
Here,
`A = `Event that chosen student is a girl.
`:. P(A) = 430/1000 = 43/100`
Let `B = `Event that chosen student studies in class XII.
`P(B) = 10% = 10/100 = 1/10`
Now, `P(AnnB) =` Probaility chosen student is from class XII and is a girl.
`=>P(AnnB) = 43/100**1/10 = 43/1000`
`:.` Required probability , `P(B/A) = (P(AnnB) )/(P(A)) = 43/1000**100/43 = 1/10.`
here we have to find `P(A|B) = ?`
Given that `P(A)=430/1000`
`P(A nn B) = ((10/100)430)/1000 `
`=43/1000`
`P(B|A) = (P( A nn B)) /(P(A))`
`=43/1000*1000/430 = 1/10`
answer