Given a fair 6-sided die, you roll once and observe the outcome n (where n is the number rolled). What is your expected value (EV) of the roll? If you are allowed one optional reroll (meaning you can choose to accept the first roll or reroll), what is your EV now? If you are allowed to reroll one additional time (meaning you can roll up to two times, always choosing whether to accept the current roll or reroll), what is your EV?