What is the covariance for the number of times a head appears for each coin? Suppose you have two unfair coins. Coin 1, denoted as C1, has a probability of landing heads with probability 2/5 and tails with probability 3/5. Coin 2, denoted as C2, has a probability of landing heads with probability 1/3 and tails with probability 2/3. Toss coin 1 first. If coin 1 lands heads, toss coin 1 again. If coin 1 lands tails, then toss coin 2.