A bag contains an unknown number of red balls and yellow balls. When N balls are drawn at random (without replacement) the probability that they are all yellow is 1/2. The number of balls in the bag is the minimum for this to happen.

If the first N balls were all yellow, what is the probability that the next ball drawn is red?

Express the probability as a function of N.

(In reply to some exceptions by Charlie)

None of those exceptions are relevant.  The problem states that  the number of balls in the bag is the minimum for the probability of all yellows to be 1/2.

Posted by Steve Herman on 2024-04-16 16:31:21