Question

4.

An unbiased dice is painted so that it has
2 red faces and 4 blue faces.
The dice is rolled twice.
(a) Copy and complete the following tree diagram:
2nd Roll of Dice
PROBABILITIES
Ist Roll of Dice
R
R
B
R
В
(b) What is the probability of obtaining at least one red face?
10 What is the probability of obtaining both faces the same colour?

Answer 1

b) Prob (at least 1 red): 2/3

Prob (R,R) = 1/9

Prob (B,B) = 4/9

Explanation:

P(at least one red): 1/3 + 1/3 = 2/3

Prob(R,R): 1/3 · 1/3 = 1/9

Prob(B,B): 2/3 · 2/3 = 4/9