Question- A bag contains n balls , one of which is white. The probability that A and B speak truth are P1 and P2 , respectively. One ball is drawn from the bag and A and B both assert it is white. Find the probability that drawn ball is actually white.
I did try and got this answer - P1P2/{(P1P2 + (n-1)(1-P1)(1-P2)}
But Answer key says - (n-1)P1P2/{((n-1)P1P2 + (1-P1)(1-P2)}
I am quite sure I get right answer but I request you guys to verify it.