A silver dollar is flipped twice. Calculate the probability of each of the following occurring:
(a) A head on the first flip
(b) A tail on the second flip given that the first toss was a head
(c) Two tails
(d) A tail on the first and a head on the second
(e) A tail on the first and a head on the second or a head on the first and a tail on the second
(f) At least one head on the two flips