Exercises in Probability: ADDITION & MULTIPLICATION RULES
Given each of the questions below, check the most appropriate response.
1. According to NCHS, between 1988 - 91, 33.3% of U.S. adults 20 years of age and over were overweight. If two people in the U.S. are selected at random, what is the probability that both are overweight?
P(both overweight) = 11.1%.
P(both overweight) = 88.9%.
P(both overweight) = 0.0%.
P(both overweight) = 100.0%.
2. A bag of M & M's in my office had the following color break down, 6 red, 4 blue, 4 green, 7 yellow, 1 orange, and 24 brown (and unfortunately, 0 gray). If an M & M is randomly selected, what is the probability that the M & M is either red or blue?
P(red or blue) = 0.130.
P(red or blue) = 0.087.
P(red or blue) = 0.152.
P(red or blue) = 0.217.
3. Given a well shuffled deck of standard playing cards, what is the probability of randomly selecting either a red card or a queen?
P(red card or queen) = 0.577.
P(red card or queen) = 0.038.
P(red card or queen) = 0.462.
P(red card or queen) = 0.539.
4. Given a well shuffled deck of standard playing cards, what is the probability of randomly selecting an even numbered card?
P(even numbered card) = 20/52.
P(even numbered card) = 22/52.
P(even numbered card) = 4/52.
P(even numbered card) = -20/52.
5. According to The Digest of Education Statistics 1996, 78.0% of U.S. 13-year-olds were able to perform numerical operations and beginning problem solving. If five 13- year-olds are randomly selected, what is the probability that none of them can perform numerical operations and beginning problem solving?
P(none can perform beginning problem solving) = 0.0005.
P(none can perform beginning problem solving) = 0.9995.
P(none can perform beginning problem solving) = 1.0000.
P(none can perform beginning problem solving) = 0.7800.
6. According to the Labor Force Statistics from the Current Population Survey, in 1996, 52.8% of families have both the husband and wife employed. If 3 famililes are randomly selected, what is the probability that they all have both spouses employed?
P(both employed) = 47.2%.
P(both employed) = 14.7%.
P(both employed) = 85.3%.
P(both employed) = 52.7%.
7. According to NCHS, 39% of the births occurring in the last 5 years to women who were betweeen 15 - 44 years of age in 1998, were unintended. (SOURCE: "Unintended Pregnancy and Childbearing" by Linda J. Piccinino, Lynn Wilcox, and James Marks, edits, From Data to Action.) If 6 new mothers are randomly selected, what is the probability that at least one of their births was unintended?
P(at least one is unintended) = 94.8%.
P(at least one is unintended) = 99.6%
P(at least one is unintended) = 0.35%.
P(at least one is unintended) = 5.15%
8. When answering questions involving the multiplication rule of probability, what is the "key" question that you should ask yourself?
Are the two events mutually exclusive?
Are the two events independent?
Do I care about these two events?
None of the above.
Copyright © 1998 Donna Tupper.
