Simple Complement Probability

P(not A) = 
*Remember to simplify.*

• 6/8

• 3/4

• 2/8

• 1/4

Answer explanation

To find P(not A), subtract P(A) from 1. Since P(A) = 1/4, P(not A) = 1 - 1/4 = 3/4. Therefore, the correct answer is 3/4.

A box contains 4 red pencils, 6 blue pencils, 5 black pencils, and 3 green pencils. The best description of the likelihood of selecting a blue pencil at random from the box is ​​​ (a)   . ​ ​

• unlikely

• impossible

• equally likely

• likely

• certain

Answer explanation

The best description of the likelihood of selecting a blue pencil at random from the box is unlikely because there are only 6 blue pencils out of a total of 18 pencils in the box.

Which of the following best describes the likelihood of the spinner landing on a number less than 6?

• impossible

• unlikely

• equally likely

• likely

• certain

Answer explanation

The likelihood of the spinner landing on a number less than 6 is 'likely' because there are 5 numbers less than 6 on the spinner, making it a probable outcome.

The likelihood that an event will occur

• Outcome

• Probability

• Experiment

• Certain

Answer explanation

The likelihood that an event will occur is referred to as Probability, making it the correct choice among the options provided.

Please label the Probability number line.

a

b

c

d

e

Certain

Unlikely

Equally Likely

Likely

Impossible

Which of the following best describes the likelihood of the spinner landing on an even number?

• impossible

• unlikely

• equally likely

• likely

• certain

Answer explanation

The spinner landing on an even number is equally likely because there are an equal number of even and odd numbers on a standard spinner.

Which of the following expressions would be used to calculate the complement of an event occurring?

• P(event) - 1

• P(event 1) x    P(event 2)

• P(event)/possible outcomes

• 1 - P(event)

The extent to which something is likely to occur is known as - 

• sample space

• an event

• probability

• data

The likelihood that a single, specific event will occur is called - 

• sample space

• compound probability

• a complement

• simple probability

In probability theory, the sum of an event (A) occurring and the same event NOT occurring (not A) is always - 

• 0

• based on the sample space

• variable

• 1