Can someone help?

A coin is tossed three times. An outcome is represented by a string of the sort HTT (meaning a head on the first toss, followed by two tails). The 8 outcomes are listed in the table below. Note that each outcome has the same probability. For each of the three events in the table, check the outcome(s) that are contained in the event. Then, in the last column, enter the probability of the event. Outcomes Probability THT HHT THH TIT HTT TTH HHH HTH X Event A: Two or more tails O O O O O Event B: Exactly one head O O O O O Event C: A tall on both the first and the last .0 O 0 O tosses