In Halloween Laura and her brother Mike arrive at a house where they oer them a

bowl with 2 chocolate bars. Mike grabs a random number of chocolate bars; he grabs 0, 1, or

2 with the same probability. Laura then grabs some chocolate bars out of the remaining ones;

also with uniform probability (there is the same probability that she grabs 0, 1, etc.).

a. Model the number of bars grabbed by Mike and the number of bars grabbed by Laura as random variables and compute their joint pmf.

b. Compute the marginal pmf of the number of bars grabbed by Laura.

c. What is the conditional pmf of the number of bars grabbed by Mike if we know that Laura grabbed 1 bar?