Download tree diagram

Lesson 9-2 Pages 374-377
Tree Diagrams
Lesson Check 9-1
What you will learn!
How to use tree diagrams
to count outcomes and
find probabilities.
Fair game
Tree diagram
Sample space
What you really need to know!
A game in which players of equal
skill have an equal chance of
winning is a fair game. A tree
diagram is used to show all of
the possible outcomes, or
sample space, in a probability
experiment.
Link to Pre-Made Lesson
Example 1:
Tom flips two coins. Draw a
tree diagram to show the
sample space of how the
coins can land. Then
determine the probability of
flipping two tails.
First
Coin
H
T
Second
Coin
Sample
Space
H
HH
T
HT
H
TH
T
TT
The probability of
flipping two tails is:
favorable 1
P(tails) 

possible
4
Example 1: Method 2
Choices x Choices =
Number of outcomes
2 x 2 = 4 possibilities
favorable 1
P(tails) 

possible
4
Example 2:
An ice cream sundae at the
Ice Cream Shoppe is made
from one flavor of ice cream
and one topping. For ice
cream flavors, you can
choose from chocolate,
vanilla, and strawberry.
Example 2:
For toppings you can have
hot fudge, butterscotch, or
marshmallow. Find the
number of different sundaes
that are possible.
Ice Cream
9 possibilities!
C
V
S
Topping
Sample Space
F
B
CF
CB
M
CM
F
B
VF
M
F
VB
VM
SF
B
M
SB
SM
Example 2: Method 2
Choices x Choices =
Number of outcomes
3 x 3 = 9 possibilities
Example 3:
If you are given a sundae at
random from the shop in the
previous problem, what is the
probability that it has vanilla ice
cream?
Ice Cream
9 possibilities!
C
V
S
Topping
Sample Space
F
B
CF
CB
M
CM
F
B
VF
M
F
VB
VM
SF
B
M
SB
SM
Example 3:
If you are given a sundae at
random from the shop in the
previous problem, what is the
probability that it has vanilla ice
cream?
favorable 3 1
P(vanilla) 
 
possible 9 3
Page 376
Guided Practice
#’s 3-6
Read:
Pages 374-375
with someone at
home and study
examples!
Homework: Page 376-377
#’s 7-19 all
#’s 23-33
THQ 9-1/9-2 Tree Diagrams
Lesson Check 9-2
Page
585
Lesson 9-2
Lesson Check 9-2
Example 1:
A family has two children.
Draw a tree diagram to show
the sample space of the
children’s genders. Then
determine the probability of
the family having two girls.
First
Child
B
G
Second
Child
Sample
Space
B
BB
G
BG
B
GB
G
GG
The probability of
having two girls is:
favorable 1
P(girls) 

possible
4
THQ 9-1 to 9-2
Tree Diagrams
#4
Y
R
B
G
B
G
YRBG
G
B
YRGB
R
G
YBRG
G
R
YBGR
G
R
B
YGRB
B
R
YGBR
Y
B
G
RYBG
G
B
RYGB
Y
G
RBYG
G
Y
RBGY
Y
B
RGYB
B
Y
RGBY
R
G
BYRG
G
R
BYGR
Y
G
BRYG
G
Y
BRGY
Y
R
BGYR
R
Y
BGRY
Y
R
B
GYRB
B
R
GYBR
R
Y
B
GRYB
B
Y
GRBY
Y
R
GBYR
R
Y
GBRY
R
B
B
G
Y
R
G
B
#5
R
B
CAR1
R CAR1
CAR2
R CAR2
CAR3
R CAR3
CAR4
R CAR4
CAR1
B CAR1
CAR2
B CAR2
CAR3
B CAR3
CAR4
B CAR4