There are 2 players , say A and B . There are m+n+1 cards and A gets m cards and B gets n cards. 1 card is left behind. A personality is linked with each card. The game begins as A begins to guess the left out card . If B has the card, he has to show the card. Else the judge checks the result if A is sure of his guess. Next turn goes to B . The game proceeds in this way. Now , what is the probability that A will win ? The probability must be accurate to 9 decimal places.
ans:0.500000000