13.7 Probability
Models over a sample space, equally likely outcomes, unions and complements of events, and odds computed with permutations.
87 exercises
Basic Probability. (Simple intro to sample spaces)
Tossing a coin:
- ⓐ Describe in set notation the sample space of tossing a coin.
- ⓑ Find the probability of “Coin lands on heads.”
Rolling a die:
- ⓐ Describe in set notation the event “Rolling an odd number.”
- ⓑ Find the probability of “Rolling an odd number.”
Drawing a card:
- ⓐ Describe in set notation the event “Drawing an Ace.”
- ⓑ Find the probability of “Drawing an Ace.”
Constructing a Probability Model
Construct a probability model for rolling a single, fair die, with the event being the number shown on the die.
13.7 Exercise 5
Construct a probability model for tossing a fair coin.
Computing the Probability of an Event with Equally Likely Outcomes
A six-sided number cube is rolled. Find the probability of rolling an odd number.
13.7 Exercise 7
A number cube is rolled. Find the probability of rolling a number greater than 2.
Computing the Probability of the Union of Two Events
A card is drawn from a standard deck. Find the probability of drawing a heart or a 7.
13.7 Exercise 9
A card is drawn from a standard deck. Find the probability of drawing a red card or an ace.
Computing the Probability of the Union of Mutually Exclusive Events
A card is drawn from a standard deck. Find the probability of drawing a heart or a spade.
13.7 Exercise 11
A card is drawn from a standard deck. Find the probability of drawing an ace or a king.
Using the Complement Rule to Calculate Probabilities
Two six-sided number cubes are rolled.
- ⓐFind the probability that the sum of the numbers rolled is less than or equal to 3.
- ⓑFind the probability that the sum of the numbers rolled is greater than 3.
13.7 Exercise 13
Two number cubes are rolled. Use the Complement Rule to find the probability that the sum is less than 10.
Computing Probability Using Counting Theory
A child randomly selects 5 toys from a bin containing 3 bunnies, 5 dogs, and 6 bears.
- ⓐFind the probability that only bears are chosen.
- ⓑFind the probability that 2 bears and 3 dogs are chosen.
- ⓒFind the probability that at least 2 dogs are chosen.
13.7 Exercise 15
A child randomly selects 3 gumballs from a container holding 4 purple gumballs, 8 yellow gumballs, and 2 green gumballs.
- ⓐFind the probability that all 3 gumballs selected are purple.
- ⓑFind the probability that no yellow gumballs are selected.
- ⓒFind the probability that at least 1 yellow gumball is selected.
13.7 Exercise 16
What term is used to express the likelihood of an event occurring? Are there restrictions on its values? If so, what are they? If not, explain.
13.7 Exercise 18
What is an experiment?
13.7 Exercise 20
The union of two sets is defined as a set of elements that are present in at least one of the sets. How is this similar to the definition used for the union of two events from a probability model? How is it different?
13.7 Exercise 22
Landing on a vowel
13.7 Exercise 24
Landing on purple or a vowel
13.7 Exercise 26
Landing on green or blue
13.7 Exercise 28
Not landing on yellow or a consonant
13.7 Exercise 30
Two coins are tossed.
Find the probability of tossing two heads.
13.7 Exercise 32
Two coins are tossed.
Find the probability of tossing at least one tail.
13.7 Exercise 34
Four coins are tossed.
Find the probability of tossing exactly two heads.
13.7 Exercise 36
Four coins are tossed.
Find the probability of tossing four heads or four tails.
13.7 Exercise 38
Four coins are tossed.
Find the probability of tossing not all tails.
13.7 Exercise 40
Four coins are tossed.
Find the probability of tossing either two heads or three heads.
13.7 Exercise 42
One card is drawn from a standard deck of cards. Find the probability of drawing the following:
A two
13.7 Exercise 44
One card is drawn from a standard deck of cards. Find the probability of drawing the following:
Red six
13.7 Exercise 46
One card is drawn from a standard deck of cards. Find the probability of drawing the following:
A non-ace
13.7 Exercise 48
Two dice are rolled, and the results are summed.
Construct a table showing the sample space of outcomes and sums.
13.7 Exercise 50
Two dice are rolled, and the results are summed.
Find the probability of rolling at least one four or a sum of
13.7 Exercise 52
Two dice are rolled, and the results are summed.
Find the probability of rolling a sum greater than or equal to
13.7 Exercise 54
Two dice are rolled, and the results are summed.
Find the probability of rolling a sum less than or greater than
13.7 Exercise 56
Two dice are rolled, and the results are summed.
Find the probability of rolling a sum of or
13.7 Exercise 58
A coin is tossed, and a card is pulled from a standard deck. Find the probability of the following:
A head on the coin or a club
13.7 Exercise 60
A coin is tossed, and a card is pulled from a standard deck. Find the probability of the following:
A head on the coin or a face card
13.7 Exercise 62
Use this scenario: a bag of M&Ms contains blue, brown, orange, yellow, red, and green M&Ms. Reaching into the bag, a person grabs 5 M&Ms.
What is the probability of getting all blue M&Ms?
13.7 Exercise 64
Use this scenario: a bag of M&Ms contains blue, brown, orange, yellow, red, and green M&Ms. Reaching into the bag, a person grabs 5 M&Ms.
What is the probability of getting blue M&Ms?
13.7 Exercise 66
Use the following scenario for the exercises that follow: In the game of Keno, a player starts by selecting numbers from the numbers to After the player makes his selections, winning numbers are randomly selected from numbers to A win occurs if the player has correctly selected or of the winning numbers. (Round all answers to the nearest hundredth of a percent.)
What is the percen…
13.7 Exercise 68
Use the following scenario for the exercises that follow: In the game of Keno, a player starts by selecting numbers from the numbers to After the player makes his selections, winning numbers are randomly selected from numbers to A win occurs if the player has correctly selected or of the winning numbers. (Round all answers to the nearest hundredth of a percent.)
What is the percen…
13.7 Exercise 70
Use the following scenario for the exercises that follow: In the game of Keno, a player starts by selecting numbers from the numbers to After the player makes his selections, winning numbers are randomly selected from numbers to A win occurs if the player has correctly selected or of the winning numbers. (Round all answers to the nearest hundredth of a percent.)
How much less is…
13.7 Exercise 72
Use this data for the exercises that follow: In 2013, there were roughly 317 million citizens in the United States, and about 40 million were elderly (aged 65 and over).
If you meet five U.S. citizens, what is the percent chance that exactly one is elderly? (Round to the nearest tenth of a percent.)
13.7 Exercise 74
Use this data for the exercises that follow: In 2013, there were roughly 317 million citizens in the United States, and about 40 million were elderly (aged 65 and over).
If you meet five U.S. citizens, what is the percent chance that four are elderly? (Round to the nearest thousandth of a percent.)
13.7 Exercise 76
Write the first four terms of the sequence defined by the recursive formula
13.7 Exercise 78
Write the first four terms of the sequence defined by the explicit formula
13.7 Exercise 80
Is the sequence arithmetic? If so, find the common difference.
13.7 Exercise 82
An arithmetic sequence has the first term and common difference What are the first five terms?
13.7 Exercise 84
Write a recursive formula for the arithmetic sequence
13.7 Exercise 86
Write an explicit formula for the arithmetic sequence
13.7 Exercise 88
Find the common ratio for the geometric sequence
13.7 Exercise 90
A geometric sequence has terms and . What are the first five terms?
13.7 Exercise 92
What are the first five terms of the geometric sequence
13.7 Exercise 94
Write an explicit formula for the geometric sequence
13.7 Exercise 96
Use summation notation to write the sum of terms from to
13.7 Exercise 98
Use the formula for the sum of the first terms of an arithmetic series to find the sum of the first eleven terms of the arithmetic series 2.5, 4, 5.5, … .
13.7 Exercise 100
Use the formula for the sum of the first n terms of a geometric series to find for the series
13.7 Exercise 102
Find the sum of the infinite geometric series
13.7 Exercise 104
Alejandro deposits $80 of his monthly earnings into an annuity that earns 6.25% annual interest, compounded monthly. How much money will he have saved after 5 years?
13.7 Exercise 106
How many ways are there to choose a number from the set that is divisible by either or
13.7 Exercise 108
How many ways are there to construct a 4-digit code if numbers can be repeated?
13.7 Exercise 110
Calculate
13.7 Exercise 112
Calculate
13.7 Exercise 114
How many subsets does the set have?
13.7 Exercise 116
How many distinct ways can the word DEADWOOD be arranged?
13.7 Exercise 118
Evaluate the binomial coefficient
13.7 Exercise 120
Use the Binomial Theorem to write the first three terms of
13.7 Exercise 122
Assume two die are rolled.
Construct a table showing the sample space.
13.7 Exercise 124
Assume two die are rolled.
What is the probability of rolling a pair?
13.7 Exercise 126
Assume two die are rolled.
What is the probability that a roll doesn’t include a 2 or result in a pair?
13.7 Exercise 128
Assume two die are rolled.
What is the probability that a roll includes neither a 5 nor a 6?
13.7 Exercise 130
Use the following data: An elementary school survey found that 350 of the 500 students preferred soda to milk. Suppose 8 children from the school are attending a birthday party. (Show calculations and round to the nearest tenth of a percent.)
What is the percent chance that at least one of the children attending the party prefers milk?
13.7 Exercise 132
Use the following data: An elementary school survey found that 350 of the 500 students preferred soda to milk. Suppose 8 children from the school are attending a birthday party. (Show calculations and round to the nearest tenth of a percent.)
What is the percent chance that exactly 3 of the children attending the party prefer milk?
13.7 Exercise 133
Write the first four terms of the sequence defined by the recursive formula
13.7 Exercise 135
Is the sequence arithmetic? If so find the common difference.
13.7 Exercise 137
Write a recursive formula for the arithmetic sequence and then find the 22nd term.
13.7 Exercise 139
Is the sequence geometric? If so find the common ratio. If not, explain why.
13.7 Exercise 141
Write a recursive formula for the geometric sequence
13.7 Exercise 143
Use summation notation to write the sum of terms from to
13.7 Exercise 145
Use the formula for the sum of the first terms of a geometric series to find
13.7 Exercise 147
Ramla deposits $3,600 into a retirement fund each year. The fund earns 7.5% annual interest, compounded monthly. If she opened her account when she was 20 years old, how much will she have by the time she’s 55? How much of that amount was interest earned?
13.7 Exercise 149
A buyer of a new sedan can custom order the car by choosing from 5 different exterior colors, 3 different interior colors, 2 sound systems, 3 motor designs, and either manual or automatic transmission. How many choices does the buyer have?
13.7 Exercise 151
A music group needs to choose 3 songs to play at the annual Battle of the Bands. How many ways can they choose their set if they have 15 songs to pick from?
13.7 Exercise 153
How many distinct ways can the word EVANESCENCE be arranged if the anagram must end with the letter E?
13.7 Exercise 155
Find the seventh term of without fully expanding the binomial.
13.7 Exercise 157
What is the probability of landing on an odd number?
13.7 Exercise 159
What is the probability of landing on blue or an odd number?
13.7 Exercise 161
A bowl of candy holds 16 peppermint, 14 butterscotch, and 10 strawberry flavored candies. Suppose a person grabs a handful of 7 candies. What is the percent chance that exactly 3 are butterscotch? (Show calculations and round to the nearest tenth of a percent.)
Adapted from College Algebra © 2021 Rice University. Licensed under CC BY 4.0. Sources: College Algebra 2e, Algebra and Trigonometry 2e, Precalculus 2e, College Algebra with Corequisite Support 2e. Imported at revision 4922e46.