A fair coin is tossed trice. Let X be the number of tails that are observed.

Question

Construct the probability distribution of X.

Answer 1

P(0) = (1/2)^3 = 1/8

P(1) = 3/8

P(2) = 3/8

P(3) =1/8

outcomes are

HHH one way to get 0 tails

HTH

HHT

THH 3 ways to get 1 tail

TTH

THT

HTT 3 ways to get 2 tails

TTT one way to get 3 tails

8 possible out comes

with 1/8, 3/8, 3/8 and 1/8 as the probabilities of 0, 1, 2 and 3 tails

if you flip the coin 3 times. thrice. trice? once is 1 time, twice is 2 times. 3 times is thrice?