please help

Problem 1. Suppose we have two boxes containing nR red and no green balls. At step k we pick a red ball uniformly at random, and a green ball uniformly at random, and switch their locations. Let Xx be the number of red balls in box one. Note, Xo = nR and Xk changes only when the selected balls were in different boxes. (a) State the state space S for the process X = {Xk}KEN. State the possible transitions, compute their probabilities and draw the transition diagram. (b) Compute E(Xk) for any k E R and find the limit as k 1 co