Page 122 - Probability Demystified

CHAPTER 6 The Counting Rules 111

8. If a board of directors consists of 10 people, in how many ways can
a chief executive officer, a director, a treasurer, and a secretary be
selected?
a. 5040
b. 210
c. 40
d. 14

9. How many different flag signals can be made from 3 red flags, 2 green
flags, and 2 white flags?
a. 49
b. 84
c. 210
d. 320

10. In how many ways can 3 boxes of cereal be selected for testing from
12 boxes?
a. 36
b. 220
c. 480
d. 1320
11. In how many ways can a jury of 5 men and 7 women be selected from
10 men and 10 women?
a. 120
b. 252
c. 372
d. 30,240

12. A phone extension consists of 3 digits. If all the digits have a prob-
ability of being selected, what is the probability that the extension
consists of the digits 1, 2, and 3 in any order? Repetitions are allowed.
a. 0.555
b. 0.006
c. 0.233
d. 0.125
13. Three cards are selected at random; what is the probability that they
will all be clubs?
a. 0.002
b. 0.034
c. 0.013
d. 0.127