a games is played on a board marked off into a line of four squares. a player starts on the square numbered 2. on each turn, a six-sided die is thrown, and the players moves one square to the left if the die comes up 5 or 6, and one square to the right otherwise. the game ands when the player reaches either and of the board (square 1 or square 4).
a/ let x is the numbers of moves until the game ends. find the frequency function of x
b/ find E(x)
c/ find Var(x).