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?

Explanation

Let E = Two ball choosen is white


A: = 2 white balls in the bag


B : 3 white balls in the bag


C : 4 white balls in the bag


` {P}(A)={P}(B)={P}(C)=1 / 3`



`P(frac{E}{A})=frac{{ }^{2} C_{2}}{{ }^{4} C_{2}}=frac{1}{6} `


`P(frac{E}{B})=frac{{ }^{3} C_{2}}{{ }^{4} C_{2}}=frac{3}{6} `


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