PROBABILITY (EXAMPLE & EXERCISE)

EXAMPLE


 A coin flipped twice. Draw a tree diagram to show all the possible outcomes.

OUTCOMES PROBABILITIES

HH 1/2 x 1/2 = 1/4

HT 1/2 x 1/2 = 1/4

TH  1/2 x 1/2 = 1/4

TT  1/2 x 1/2 = 1/4

EXERCISE

a) What is the probability of getting blue twice?

BB = 1/5 x 1/5  =  1/25

b) What is the probability of not getting blue twice?

BR = 1/5 x 4/5  =  4/25

RB = 4/5 x 1/5  =  4/25

RR = 4/5 x 4/5  =  16/25

4/25 + 4/25 + 16/25  =  24/25

c) What is the probability of getting the same color twice?

BB = 1/5 x 1/5 = 1/25

RR = 4/5 x 4/5 = 16/25

1/25 + 16/25 = 17/25

d) What is the probability of getting different colors?

BR = 1/5 x 4/5 = 4/25

RB = 4/5 x 1/5 = 4/25

4/25 + 4/25 = 8/25