Suppose two slot Machines are available. Machine A costs $1 to play and with probability (1/3), returns $2 and, with probability (2/3), returns nothing. Machine B also costs $1 to play, but with probability (1/6) returns $4 and with probability (5/6) returns nothing. Consider the following play methods. (1) Play machine A first; if you win, Play A again,; otherwise switch to B. (2) Play machine B first, if you win, play b Again; otherwise switch to A. a)Find the mean and variance of the two possible play methods.