Question

While cleaning her dorm room, Monica mistakenly pushed three coins off the desk. When they land on the chair below, find the odds
(a) in favor of getting exactly three heads
(b) in favor of getting exactly three tails
(c) against getting exactly two heads
(d) against getting exactly one tail
(e) in favor of getting at least one tail

Answer 1

Assuming all three coins are fair, you could use a probability tree or a table to list all possible outcomes (Ω) and calculate the probabilities accordingly.
H=head
T=tail

All 8 possible outcomes
HHH
HHT
HTH
HTT
HHH
THT
TTH
TTT

You can use the table to answer the above questions.