1. what is the probability of tossing at least 3 "heads" if a fair coin is tosses for times?

2. of the 15 teams in the NHL , three of them are based in Canadian cities. Each year of these teams qualify for the playoffs. Assuming all 15 teams have an equal chance of getting into the playoffs, what is the probability that:

a. none of the Canadian teams make the playoffs?

b. at least one of the Canadian teams makes the playoffs?

c. all three Canadian teams make the playoffs?

Please if someone can help me by showing me the work rather than just giving me the answer so I could learn due to me struggling to solve this.

Thank you very much