Understanding Complementary Events

What are complementary events in probability?

• Events that have no relation to each other

• Events that are always independent of one another

• Events that cannot occur simultaneously

• Complementary events are pairs of outcomes in probability that together encompass all possible outcomes, where the occurrence of one event means the other cannot occur.

If the probability of an event A is 0.7, what is the probability of its complementary event?

• 0.5

• 0.3

• 0.9

• 0.1

In a class of 30 students, 18 are girls. What is the probability of randomly selecting a boy?

• 0.6

• 0.5

• 0.3

• 0.4

If the probability of raining tomorrow is 0.4, what is the probability that it will not rain?

• 0.8

• 0.6

• 0.2

• 1.0

Explain how complementary events can be used in real-life situations.

• Complementary events are irrelevant in business decision-making.

• Complementary events can predict exact outcomes in sports.

• Complementary events can be used to simplify decision-making in uncertain situations, such as weather forecasts or risk assessments.

• Complementary events are only applicable in mathematical contexts.

A die is rolled. What is the probability of not rolling a 3?

• 1/2

• 4/6

• 5/6

• 2/3

If the probability of winning a game is 0.25, what is the probability of losing?

• 0.50

• 0.75

• 0.10

• 0.90

In a survey, 60% of people prefer tea over coffee. What is the probability that a randomly selected person prefers coffee?

• 0.5

• 0.2

• 0.4

• 0.3

If the chance of passing a test is 0.85, what is the chance of failing?

• 0.10

• 0.50

• 0.15

• 0.25

Provide an example of complementary events in sports.

• Team A wins and Team A does not win.

• Team A ties with Team B

• Team A loses and Team B wins

• Team A scores more points than Team B