Page 83 - Probability Demystified

72 CHAPTER 4 The Multiplication Rules

7. If three people are randomly selected, find the probability that they
will all have birthdays in June.

1
a.
1728
1
b.
36
1
c.
12
1
d.
4
8. In a sample of 10 telephones, 4 are defective. If 3 are selected
at random and tested, what is the probability that all will be non-
defective?

1
a.
30
8
b.
125
1
c.
6
27
d.
125

9. A bag contains 4 blue marbles and 5 red marbles. If 2 marbles are
selected at random without replacement, what is the probability that
both will be blue?

16
a.
81
1
b.
6
1
c.
2
1
d.
15