1A Probability and Simple Events
Use the spinner to find the probability. Write as a fraction in simplest form, a decimal, and a percent.
P(M )
The probability of spinning M is
, 0.125, or 12.5%.
P(Q or R)
The probability of spinning Q or R is
, 0.25, or 25%.
P(vowel)
The probability of spinning a vowel is
, 0.125, or 12.5%.
MARBLES Roberto has a bag that contains 7 blue, 5 purple, 12 red, and 6 orange marbles. Find the
probability if he draws one marble at random from the bag. Write as a fraction in simplest form.
P(purple)
The probability of choosing purple is
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P(red or orange)
.
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1A Probability
and
Simple
Events
The probability of
spinning
a vowel
is , 0.125, or 12.5%.
MARBLES Roberto has a bag that contains 7 blue, 5 purple, 12 red, and 6 orange marbles. Find the
probability if he draws one marble at random from the bag. Write as a fraction in simplest form.
P(purple)
The probability of choosing purple is
.
P(red or orange)
The probability of choosing red or orange is
.
P(green)
The probability of choosing green is 0.
P(not blue)
The probability of choosing a marble that is not blue is
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P(not red or orange)
.
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1A Probability
and
Simple
Events
The probability of
choosing
a marble
that is not blue is
.
P(not red or orange)
The probability of choosing a marble that is not red or orange is
.
P(not yellow)
The probability of choosing a marble that is not yellow is 1.
SURVEYS
If a student in her class is selected at random, what is the probability that the student does not own 3 or more pets?
Write as a fraction in simplest form.
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1A Probability and Simple Events
The probability of choosing a marble that is not yellow is 1.
SURVEYS
If a student in her class is selected at random, what is the probability that the student does not own 3 or more pets?
Write as a fraction in simplest form.
The probability that the student does not own 3 or more pets is
.
A set of 20 cards is numbered 1, 2, 3, . . ., 20. Suppose you pick a card at random without looking. Find
the probability of the event. Write as a fraction in simplest form, a decimal, and a percent.
P(1)
The probability of choosing a 1 is
, 0.05, or 5%.
P(3 or 13)
The probability of choosing a 3 or 13 is
, 0.1 or 10%.
P(multiple of 3)
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Multiples of 3 that occur between 1 and 20 are 3, 6, 9, 12, 15, and 18.
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1A Probability
and
Simple
Events
The probability of
choosing
a 3 or
13 is
, 0.1 or 10%.
P(multiple of 3)
Multiples of 3 that occur between 1 and 20 are 3, 6, 9, 12, 15, and 18.
The probability of choosing a multiple of 3 is
, 0.3 or 30%.
P(even number)
Even numbers that occur from 1 to 20 are 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20.
The probability of choosing an even number is
, 0.5, or 50%.
P(not 20)
The probability of not choosing 20 is
, 0.95, or 95%.
P(not a factor of 10)
Factors of 10 that occur from 1 to 20 are 1, 2, 5, and 10.
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1A Probability
and
Events
The probability of
not Simple
choosing 20
is
, 0.95, or 95%.
P(not a factor of 10)
Factors of 10 that occur from 1 to 20 are 1, 2, 5, and 10.
The probability of not choosing a factor of 10 is
, 0.8, or 80%.
RAFFLE The table shows the number of students in seventh grade who entered in the school drawing to
win lunch with the principal. Suppose that only one student is randomly selected to win. Find the
probability of the event. Write as a fraction in simplest form.
P(Room 8)
The probability of choosing a student from Room 8 is
P(Room 9)
The probability of choosing a student from Room 9 is
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P(Room 12)
.
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The probability of
choosing
a student
from Room 8 is
1A Probability
and
Simple
Events
P(Room 9)
The probability of choosing a student from Room 9 is
.
P(Room 12)
The probability of choosing a student from Room 12 is
.
P(Room 10)
The probability of choosing a student from Room 10 is
.
P(not Room 8)
The probability of not choosing a student from Room 8 is
.
P(Room 11)
The probability of choosing a student from Room 11 is
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P(not Room 10)
.
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1A Probability
and
The probability of
not Simple
choosing aEvents
student from Room 8 is
.
P(Room 11)
The probability of choosing a student from Room 11 is
.
P(not Room 10)
The probability not choosing a student from Room 10 is
.
P(Room 10 or 11)
The probability of choosing a student from Room 10 or Room 11 is
.
SOUP A cupboard contains 20 soup cans. Seven are tomato, 4 are cream of mushroom, 5 are chicken, and 4 are
vegetable. If one can is chosen at random from the cupboard, what is the probability that it is neither cream of
mushroom nor vegetable soup? Write as a percent.
The probability of choosing a can that is neither cream of mushroom nor vegetable soup is
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VIDEOS In a drawing, one name is randomly chosen from a jar of 75 names to receive free video rentals for a
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1A Probability
and
Simple
Events
The probability of
choosing
a student
from Room 10 or Room 11 is
.
SOUP A cupboard contains 20 soup cans. Seven are tomato, 4 are cream of mushroom, 5 are chicken, and 4 are
vegetable. If one can is chosen at random from the cupboard, what is the probability that it is neither cream of
mushroom nor vegetable soup? Write as a percent.
The probability of choosing a can that is neither cream of mushroom nor vegetable soup is
VIDEOS In a drawing, one name is randomly chosen from a jar of 75 names to receive free video rentals for a
month. If Enola entered her name 8 times, what is the probability that she is not chosen to receive the free rentals?
Write as a fraction in simplest form.
The probability that Enola is not chosen to receive free rentals is
.
PETS The graph shows the last 33 types of pets that were purchased at a local pet store.
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What is the probability that a receipt chosen at random from these sales would be for a cat or dog? Express as a
1A Probability
andEnola
Simple
The probability that
is not Events
chosen to receive free rentals is
.
PETS The graph shows the last 33 types of pets that were purchased at a local pet store.
What is the probability that a receipt chosen at random from these sales would be for a cat or dog? Express as a
percent.
The probability that a receipt chosen at random from the sales is for a cat or dog is
GAMES For a certain game, the probability of choosing a card with the number 13 is 0.008. What is the probability
of not choosing card 13?
The probability of not choosing card 13 is 0.992. This would be just to the left of 1 on the number line, which
indicates that the event is almost certain.
Therefore, it is very likely that card 13 will not be chosen.
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