There are two boxes I and II. Box I contains 3 red and 6 black balls. Box II contains 5 red
and 'n' black balls. One of the two boxes,box I and box II is selscted at random and a ball is drawn at random. The ball drawn is found to be red. If The probability that this red ball comes out from box II is find the value of 'n'.
E1 = selecting box I
E2 = selecting box II
A = geting a red ball from selescted box