1- If two balls are chosen with replacement from a box containing two red, two white and two black balls. If we let X and Y denote, respectively, the number of red and white that are chosen, then determine the joint probability distribution of X and Y.

2- If balls are chosen without replacement from a box containing two red and two white balls. If we let X denote the number of balls chosen until getting the first red ball, then determine the probability distribution of X.

3- If balls are chosen with replacement from a box containing two red and two white balls. If we let X denote the number of balls chosen until getting the first red ball, then determine the probability distribution of X.