Review of Probability Concepts

The sum of the simple probabilities for all possible outcomes of an activity must equal to:

Answer explanation

Fundamental Concepts

The probability, P, of any event or state of nature occurring is greater than or equal to 0 and less than or equal to 1. (0 <= P (event) <=1)

Probability can be written as:

• a fraction

• a decimal

• a percentage

• all of the above

An unlikely chance event is closer to what number?

• 0

• 1

• 2

• infinity

A spinner has 8 equal regions. Each region is marked with one of the following numbers: 10, 20, 30, 40, 50, 60, 70, 80. What is the probability of an even number being spun on the first roll?

• 1/8

• 1/2

• 1

• 3/8

Events are said to be _____ if only one of the events can occur on any one trial.

Answer explanation

Events are said to be mutually exclusive if only one of the events can occur on any one trial. Tossing a coin will result in either a head or a tail. Rolling a die will result in only one of six possible outcomes.

Events are said to be _____ if the list of outcomes includes every possible outcome.

Answer explanation

Events are said to be collectively exhaustive if the list of outcomes includes every possible outcome. Examples: (a) Both heads and tails as possible outcomes of coin flips; (b) All six possible outcomes of the roll of a die.

You draw one card from a deck of 52 playing cards. What is the probability of drawing a 7?

[Express your answer as a fraction: x/y]

Answer explanation

P (drawing a 7) = 4/52 = 1/13

Draw a spade and a club.

Is this a mutually exclusive event?

• Yes

• No

Draw a face card and a number card.

Is this a mutually exclusive event?

• Yes

• No

Draw a face card and a number card.

Is this a collectively exhaustive event?

• Yes

• No