8. I have two coins: one is a regular fair coin, and the other one has two heads. You choose one of the coins at random, and then toss the coin many times. You report the results of the tosses; X" is the result of the nth toss (either heads or tails, or 1 or 0). There are two states: heads and tails (or 1 and 0). (a) If the rst toss is known to be heads, what is the probability that the second toss is also heads? (This is a conditional probability question.) (b) If the rst toss is known to be tails, what is the probability that the second toss is