Transcript Simple Events - Skyline R2 School

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Objective
Find the probability of a simple event
Vocabulary
Outcome
One possible result of a probability event
Vocabulary
Simple event
One outcome or a collection of outcomes
Vocabulary
Probability
The chance that some event will happen.
A ratio
Ways an event can occur
Number of Possible Outcomes
Vocabulary
Random
Outcomes occur at random if each outcome is
equally likely to occur
Vocabulary
Complementary event
The events of one outcome happening and that
outcome not happening are complementary
events.
The sum of the probabilities of complementary
events is 1
Example 1 Find Probability
Example 2 Find Probability
Example 3 Find a Complementary Event
If the spinner is spun once, what
is the probability of it landing on
an odd number
number?
Write probability statement
Numerator is “odd numbers
possible”
Denominator is “total
numbers possible”
1/3
If the spinner is spun once, what
is the probability of it landing on
an odd number?
Count how many “odd
numbers”
1 and 3 are odd numbers
Place 2 in the numerator
1/3
If the spinner is spun once, what
is the probability of it landing on
an odd number?
Count how many “total
numbers” are on the spinner
There are 4 numbers on the
spinner
Place 4 in the denominator
1/3
If the spinner is spun once, what
is the probability of it landing on
an odd number?
2
2
Answer:
Find the GCF = 2
Divide GCF into numerator
and denominator
1/3
What is the probability of rolling a number less than
three on a number cube marked with 1, 2, 3, 4, 5, and
6 on its faces?
NOTE: A number cube is a number dice
Answer: P (number less than 3) =
1/3
The bookstore at the mall has 15 math books, 20 science
books, 10 literature books and 5 history books for a
give-away promotion. The clerk will select a book at
random to give to each customer. What is the
probability that the clerk will select a literature book?
book
P (literature book) = number of literature books
total number of books
Write probability statement
Numerator will be “number
of literature books”
Denominator will be “total
number of books”
2/3
The bookstore at the mall has 15 math books, 20 science
books, 10 literature books and 5 history books for a
give-away promotion. The clerk will select a book at
random to give to each customer. What is the
probability that the clerk will select a literature book?
book
P (literature book) = number of literature books
total number of books
P (literature book) =
10
50
Replace literature books
with 10
Count total number of
books
15 + 20 + 10 + 5 = 50
2/3
The bookstore at the mall has 15 math books, 20 science
books, 10 literature books and 5 history books for a
give-away promotion. The clerk will select a book at
random to give to each customer. What is the
probability that the clerk will select a literature book?
book
P (literature book) = number of literature books
total number of books
P (literature book) =
10  10
50  10
Answer:
1
P (literature book) =
5
Find the GCF = 10
Divide GCF into numerator
and denominator
2/3
GAMES A game requires rolling a number cube
marked with 1, 2, 3, 4, 5, and 6 on its. If the roll is four
or less, the player wins. What is the probability of
winning the game?
Answer: P (4 or less) = 2
3
2/3
GAMES A game requires spinning
the spinner. If the spin is 6 or
greater, the player wins. What is the
probability of not winning the game?
P (5 or less) =
Write probability statement
To win, must have 6 or
greater
So to lose, must have 5 or
less
3/3
GAMES A game requires spinning
the spinner. If the spin is 6 or
greater, the player wins. What is the
probability of not winning the game?
numbers 5 or less
P (5 or less) = total number of numbers
Numerator is “numbers 5 or
less”
Denominator is “total
number of numbers”
3/3
GAMES A game requires spinning
the spinner. If the spin is 6 or
greater, the player wins. What is the
probability of not winning the game?
numbers 5 or less
P (5 or less) = total number of numbers
P (5 or less) =
5
8
Count numbers that are 5 or
less
Count all the numbers
3/3
GAMES A game requires spinning
the spinner. If the spin is 6 or
greater, the player wins. What is the
probability of not winning the game?
numbers 5 or less
P (5 or less) = total number of numbers
Answer:
5
P (5 or less) =
8
Find the GCF = 1
NOTE: This is a complementary event
3/3
*
GAMES A game requires rolling a number cube
marked with 1, 2, 3, 4, 5, and 6 on its faces. If the roll
is two or less, the player wins. What is the probability
of not winning the game?
Answer: P (not winning) = 2
3
NOTE: This is a complementary event
3/3
Assignment
Lesson 9:1
Simple Events
10 - 26 All