#5 – Two Balls
Two balls, each either black or red, are placed in a bag. You draw a ball from the bag, which contains at least one red ball. If the ball you draw is red, what is the probability that the ball remaining in the bag is red too?
The Prize for This Question: Rubik’s Race
The Winner of Puzzle #3: Umar Raza
This question was prepared by Emrehan Halıcı, president of the Turkey Intelligence Foundation, for Bilkent IEEE.