7th Grade Math

Compound Events

PART A B

Multi-Part

Lesson 2

Get ConnectED

GLE 0706.5.5

Understand and apply basic

concepts of probability.

450 Probability and Predictions

Main Idea

Find the probability of

independent and

dependent events.

Vocabulary

compound event

independent events

dependent events

disjoint events

Independent and

Dependent Events

SALES A sale advertises that if you buy Type of

Item

Tote Bag

Colors

T-shirt

jacket

hat

beach towel

visor

polo shirt

green

red

white

an item from the column on the left, you

get a tote bag free. Suppose you choose

items at random.

1. What is the probability of buying a beach
   towel? receiving a red tote bag?


2. What is the product of the probabilities in
   Exercise 1?


3. Draw a tree diagram to determine the probability that someone buys
   a beach towel and receives a red tote bag.

The combined action of buying an item and receiving a free tote bag

is a compound event. A compound event consists of two or more

simple events. These events are independent events because the

outcome of one event does not affect the other event.

Probability of Independent Events

Words The probability of two independent events can be found

by multiplying the probability of the first event by the

probability of the second event.

Symbols P(A and B) = P(A) · P(B)

Independent Events

One letter tile is selected and

S

L

G B

A

T

E

A B

C

E D

F

the spinner is spun. What is

the probability that both

will be a vowel?

P(selecting a vowel) = _^2

7

P(spinning a vowel) = _^2

6

or _^1

3

P(both letters are vowels) = _^2

7

· _^1

3

or _^2

21

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