flip a coin 3 times
a) what are the odds in favor of getting exactly 2 heads
b) what are the odds against getting at most 1 tail
H H H
H H T
H T H
H T T
T T T
T T H
T H T
T H H
NOW TRY
a) what are the odds in favor of getting exactly 2 heads
b) what are the odds against getting at most 1 tail
H H T
H T H
H T T
T T T
T T H
T H T
T H H
NOW TRY