A bag contains 4 white and 5 black balls and another bag contains 3 white and 4 black balls. A ball is taken out from the first bag and without seeing its colour is put in the second bag.A ball is taken out from the latter. Find the probability that the ball drawn is white.

Explanation

`E_{1}=` black ball is put from first to second bag


`E_{2}=`white ball is put from first to second bag


`A=` white ball is drawn



`therefore P(E_{1})=frac{5}{9} `


`P(E_{2})=frac{4}{9}`


`P(A / E_{1})=frac{3}{8} `


`P(A / E_{2})=frac{4}{8}=frac{1}{2}`


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