Q24 of 45 Page 1

A bag contains 4 balls. Two balls are drawn at random and are found to be white. What is the probability that all balls are white?

Given, There are total of 4 balls in a bag.

To Find: What is the probability that all the balls are white


Explanation: We have a total 4 balls in a bag.


And, Two Balls are drawn at random and are found to be white


Let us Consider the events,


E1 = The bag contains two white and two other balls


E2 = The bag contains three white and one other ball


E3 = The bag contains all four white balls


And,


A = Two balls drawn are white.


So,


P(E1) = P(E2) = P(E3) = 1/3


2C2/4C2


2C2/4C2


2C2/4C2


According to Bayes Theorem ,






Hence, This is the required probability.


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