1 A coin is to be flipped three times List the possible outc

1. A coin is to be flipped three times. List the possible outcomes in the form: (result on toss 1, result in toss 2, result in toss 3 ). Assume that each one of the outcomes has probability 1/8 of occurring. Find the probability of

a. A : Observing exactly 2 head

b. B : Observing 2 or more heads

c. C: Observing no heads

[ hint: list out the events in A,B,C respectively, it is then easy to compute their probabilities.]

Solution

Outcomes can be

HHH,HHT,HTT,TTT,TTH,THH,THT,HTH

EXACTLY TWO HEADS

HHT,THH,HTH..PROBABILITY=3/8

2 OR MORE HEAD

HHH,THH,HTH,HHT ,,,PROBABILITY=4/8

NO HEAD

TTT....PROBABILITY=1/8