Download Practice A 8-5

Name
LESSON
Date
Class
Practice A
8-5 Disjoint Events
Determine whether each set of events is disjoint. Explain.
1. rolling a 5 or rolling an odd number on a number cube
2. choosing a cherry fruit chew or an apricot fruit chew from a box
that contains cherry, apricot, and apple fruit chews
Complete the following to find the probability of each set of
disjoint events.
3. choosing an M or an E from the letters in the word mathematics
P (M) P (M or E ) P (M ) P(E) P(E) 4. choosing a blue marble or a green marble from a bag that
contains only 4 blue marbles, 6 red marbles, and 2 green
marbles
P (blue) P(green) P (blue or green) P(blue) P(green) Nickel
Heads Tails
Sean tosses a nickel and a dime at the same time.
5. Complete the grid to show the sample space.
Dime
6. How many outcomes
are in the sample space?
7. Find the probability that
both coins land on heads.
Heads
HH
Tails
8. Find the probability that one coin lands on heads while the other
lands on tails.
9. Find the probability that both coins land on heads OR one coin
lands on heads while the other lands on tails.
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41
Holt Mathematics
Practice B
8-5 Disjoint Events
Practice A
8-5 Disjoint Events
LESSON
LESSON
Determine whether each set of events is disjoint. Explain.
Determine whether each set of events is disjoint. Explain.
1. choosing a pencil or a pen from a backpack that contains pencils, pens,
highlighters, and felt-tip markers
1. rolling a 5 or rolling an odd number on a number cube
The events are not disjoint. Because 5 is an odd number, you can roll a
The events are disjoint. You cannot choose a pencil and a pen at the
5 and an odd number at the same time.
same time.
2. choosing a cherry fruit chew or an apricot fruit chew from a box
that contains cherry, apricot, and apple fruit chews
2. choosing an even number or a multiple of 4 from among the
numbers 1–20.
The events are disjoint. You cannot choose a cherry fruit chew and an
The events are not disjoint. It is possible to choose a number that is even
apricot fruit chew at the same time.
and a multiple of 4 at the same time (for example, 4, 8, 12, 16, or 20).
Complete the following to find the probability of each set of
disjoint events.
Find the probability of each set of disjoint events.
2
11
P(E) 2
11
P(M or E ) P (M ) P(E) 1
11
1
11
4. choosing a vowel or a P from the letters in the
word apple
3
11
5. choosing a peanut or a cashew from a bowl that
contains only 10 peanuts, 5 cashews, and
10 pistachios
4. choosing a blue marble or a green marble from a bag that
contains only 4 blue marbles, 6 red marbles, and 2 green
marbles
1
3
P(blue) P(green) 1
3
P(blue or green) P(blue) P(green) 1
6
Nickel
Heads Tails
5. Complete the grid to show the sample space.
Heads
Dime
4
7. Find the probability that
both coins land on heads.
1
4
Tails
TH
8. Find the probability that
Amanda will win a prize.
1
6
TT
1
2
3
4
9. Find the probability that both coins land on heads OR one coin
lands on heads while the other lands on tails.
41
Holt Mathematics
First Number Cube
2
3
4
5
6
1
1
2
3
4
5
6
2
2
4
6
8
10
12
3
3
6
9
12
15
18
4
4
8
12
16
20
24
5
5
10 15
20
25
30
6
6
12 18
24
30
36
42
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All rights reserved.
Holt Mathematics
Review for Mastery
8-5 Disjoint Events
Practice C
8-3 Disjoint Events
LESSON
LESSON
Determine whether each set of events is disjoint. Explain.
Follow these steps to find the probability of disjoint events.
Step 1: Find the probability of each event.
Step 2: Add the probabilities of the individual events.
Step 3: Simplify the fraction, if necessary.
1. choosing a prime number or an even number from among the numbers 1–10
The events are not disjoint. Because 2 is both a prime number and an even number,
it is possible to choose a number that is prime and even at the same time.
1. Sheng has a set of cards numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. He chooses
one card at random. He wants to know the probability of choosing a card with a
number less than 4 or greater than 9.
2. choosing a reptile or a zebra from a set of 50 cards that each
show a picture of a different animal
3
10 .
1
The probability of choosing a card with a number greater than 9 is 10 .
The events are disjoint. You cannot choose an animal that is both a
Step 1: The probability of choosing a card with a number less than 4 is
reptile and a zebra.
Find the probability of each set of disjoint events.
2
3
2
5
7
10
3. rolling a prime number or a 1 on a number cube
4. choosing a number less than 5 or a number greater
than 16 from among the numbers 1–20
5. choosing a consonant or an A from the letters in
the word California
6. choosing a consonant or a vowel from the letters in
the word California
Heather rolls two number cubes.
She finds the difference of the
numbers shown on the cubes by
subtracting the smaller number
from the larger number.
Second Number Cube
8. Find the probability that the
difference of the numbers shown
on the cubes is 0 or 5.
2
9
43
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1
Step 2: The probability of choosing a card with a number less than 4 or greater
0
2
3
3
10
4
10 .
Step 3: The simplified fraction is
2
5
.
Justine has a bag that contains 9 red marbles, 7 green marbles, and 4 yellow
marbles. She chooses one of the marbles without looking.
First Number Cube
2
3
4
5
1
1
10
than 9 is
1
1
7. Complete the grid to show the
sample space.
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All rights reserved.
1
7. Complete the grid to show the
sample space.
HT
HH
8. Find the probability that one coin lands on heads while the other
lands on tails.
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
Amanda rolls two number cubes.
She wins a prize if the product of
the numbers rolled is 12 or 30.
1
2
Sean tosses a nickel and a dime at the same time.
6. How many outcomes
are in the sample space?
3
5
3
5
6. choosing an even number or a 7 from among the
numbers 1–10
1
6
Second Number Cube
P(M) 2
3
4
5
3. rolling an odd number or a 6 on a number cube
3. choosing an M or an E from the letters in the word mathematics
4
9
20
7
20
2. What is the probability that Justine chooses a red marble?
6
5
3. What is the probability that she chooses a green marble?
4. Write a sum to find the probability that Justine chooses a red
marble or a green marble.
2
1
0
1
2
3
4
3
2
1
0
1
2
3
4
3
2
1
0
1
2
5
4
3
2
1
0
1
6
5
4
3
2
1
0
9
7
16
4
20
20
20
5
Use the spinner at right to find the probability of each set of
disjoint events.
Holt Mathematics
5. the spinner lands on 1 or it lands on 5
1
4
6. the spinner lands on an even number or
it lands on 7
5
8
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All rights reserved.
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Holt Mathematics
Holt Mathematics