A bag contains 5 balls of unknown colors such that a ball is drawn at random from it and is found to be white. The probability that bag contains only white balls is

Let Wi(i=1,2,3,4,5) denotes i white balls and (5−i) denotes  other coloured balls. W denotes event of selecting white ball.PWWi=i5,(i=1,2,3,4,5)PWi=15,(i=1,2,3,4,5)Probability of occurrence of W given W5  has occurredPWW5=PW5⋅PWW5∑i=15 PWiPWWi=15×11515+25+35+45+55=13 Therefore, the correct answer is 0.33        Baye's theorem