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the shortcut of bayes theorem , or the meaning one
@Apu
Note for OP
+solved @user1 @user2... to close the thread when your doubt is solved. Mention the users who helped you solve the doubt. This will be added to their stats.You have to use bayes' here are probability of choosing a ball from bag A is greater than choosing a ball from bag B.
n(white in A)/n(white) would imply that the probability of each white ball being picked up is same which is not the case.
Bayes theorem
why this
both are 1/2 na?
Oohhhh got it
Its the order
P(B/A) hai ye
not P(A/B)
conditions are reversed
In the sense that agar you put all the balls in one bag and pick one at random, the prob that ball was from B is less than it prob of it being in A
no choosing ball will be same from both
u can say if we choose white from A
that will be lower than if we choose white from B
so cant do what i did
Yeah again in the sense that if you empty all bags into one big bag and then choose, the probability of choosing a ball and it being from B is less than in A. For instance, if B had 5 white and 5 black balls, the probability of white ball being from A is (1/2*3/10)/1/2(3/1+5/10)=3/8 from bayes' and 3 white balls/ 8 total white balls from the other method.
The key is that each event that you consider a "unit" must be equally likely.