A box consists of some balls, of which 2 are red, 2 are blue, and others are green. Randomly draw 2 balls from the box without replacement. The probability of getting 1 green ball is 8/15. What's the number of green balls in this box such that the total number of balls is smallest?
Suppose there are 2 green balls in the box. Each time we draw 4 balls from this box randomly with replacement and call this a set of draws. Repeat this until in a single set of draws, you get at least one ball from each different color. What is the expected number of drawings?
Suppose there are 4n-4 green balls and you draw one ball each time with replacement for n times. What's the distribution of the total number of red balls drawn? If n goes to infinity, what would that distribution be?