Answer
We toss 3 coins in the air.
Work Step by Step
(a) The probability of getting either 1 Head or 2 Heads out of 3 flips of a coin is .75.
P(1 Head or 2 Heads out of 3 flops) = P(1 Head) + P(2 Heads) = .3750 + .3750 = .75
(b) The probability of getting either all Heads or no Heads out of 3 flips of a coin is .25
P(all Heads or no Heads out of 3 flips) = P(3 Heads) + P(0 Heads) = .1250 + .1250 = .25