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Lesson

Complementary and Equally Likely Events

When all outcomes in a sample space are equally likely, the probability of an event is given by:

40min lesson

Objectives3 goals Lesson12 blocks Review9 assets Practice32 items

Learning objectives

What to understand

3 goals

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Understand complementary and equally likely events in the Probability chapter.
Connect the idea with formulas, examples, and exam-style questions.
Use flashcards, notes, MCQs, and LAQs to check readiness.

Lesson

Step-by-step lesson

12 sections

Concept

Trial and Event

A trial is an action whose outcome is uncertain. An event is a collection of one or more outcomes of a trial. 💡 Exam Tip: Write the sample space first whenever possible, then count favourable outcomes carefully. Use the complement rule when that makes counting easier. ⚠️ Common Mistake: Students often skip the sample space and miscount total outcomes or favourable outcomes. 📌 Trigger: Favourable ÷ total

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12 lesson sections6 cards / 3 notes18 MCQs / 14 written questions

Lesson Notes Flashcards Revision MCQs Written answers Topic test

Notes

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3 notes

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1
Classical Probability Formula
2
Complementary Events
3
Equally Likely vs. Unequally Likely Outcomes

Practice

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32 prompts

18 MCQs14 LAQsMixed test

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In this chapter

Probability

Topic 5 of 7

Now on Complementary and Equally Likely Events. Next up: Coins, Dice, and Compound Events.

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Classical Probability Formula
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Coins, Dice, and Compound Events
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Complementary and Equally Likely Events

What to understand

Step-by-step lesson

Trial and Event

Trial and Event example

Sample Space

Sample Space example

Favourable Outcomes

Favourable Outcomes example

Probability Formula

Probability Formula example

Drawing a Card from a Deck

Classical Probability Formula

Complementary Events

Equally Likely vs. Unequally Likely Outcomes

Trial and Event

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Note highlights

Classical Probability Formula

Complementary Events

Equally Likely vs. Unequally Likely Outcomes

Check this topic

Probability

Mark this topic complete

Around this topic

Complementary and Equally Likely Events

What to understand

Step-by-step lesson

Trial and Event

Trial and Event example

Sample Space

Sample Space example

Favourable Outcomes

Favourable Outcomes example

Probability Formula

Probability Formula example

Drawing a Card from a Deck

Classical Probability Formula

Complementary Events

Equally Likely vs. Unequally Likely Outcomes

Trial and Event

Choose your next activity

Note highlights

Classical Probability Formula

Complementary Events

Equally Likely vs. Unequally Likely Outcomes

Check this topic

Probability

Mark this topic complete

Around this topic