Grade 12 · Data, Statistics & Probability

Combinatorics and Probability

Learn to measure likelihood and compare possible outcomes through clear explanations, worked examples, an interactive model, and guided practice.

Curriculum placementGrade 12 progression · Data, Statistics & Probability30 minute lesson
Structured mathInteractive visual150-question practice bankNo account required

Lesson coverage

Learn the whole topic, not just one problem type.

This lesson and its practice bank deliberately rotate across these core facets so students build a connected understanding of the subject.

Sample space

List and count possible outcomes.

Simple probability

Compare favorable outcomes with total outcomes.

Compound events

Reason about more than one event.

Models

Compare theoretical and experimental probability.

Applications

Use probability to make and evaluate predictions.

Learning goalUse combinatorics and probability accurately, explain the reasoning, and apply the idea to unfamiliar problems.
Why it mattersCombinatorics and Probability strengthens the quantitative reasoning used in later mathematics, science, technology, and financial decision-making.
01Lesson step

Build the idea

Combinatorics and Probability is part of the integrate advanced functions, modeling, trigonometry, vectors, matrices, statistics, and introductory calculus ideas. Start by identifying what each quantity, symbol, diagram, or graph represents before calculating.

02Lesson step

Sample space

List and count possible outcomes. Use a representation that fits the idea, connect it to the relevant mathematical relationship, and explain how the representation supports the result.

03Lesson step

Simple probability

Compare favorable outcomes with total outcomes. Use a representation that fits the idea, connect it to the relevant mathematical relationship, and explain how the representation supports the result.

04Lesson step

Compound events

Reason about more than one event. Use a representation that fits the idea, connect it to the relevant mathematical relationship, and explain how the representation supports the result.

05Lesson step

Models

Compare theoretical and experimental probability. Use a representation that fits the idea, connect it to the relevant mathematical relationship, and explain how the representation supports the result.

06Lesson step

Applications

Use probability to make and evaluate predictions. Use a representation that fits the idea, connect it to the relevant mathematical relationship, and explain how the representation supports the result.

07Lesson step

Use a reliable strategy

Identify what the data or outcomes represent, choose an appropriate summary or probability model, calculate, then interpret the result in context.

08Lesson step

Check and explain

A correct answer is only part of mathematical understanding. Check units, signs, scale, and whether the result makes sense. Then explain the relationship in words so you can recognize the same structure when the numbers or context change.

Key terms

Words to know

Combinatorics and Probability
The central skill or relationship explored in this lesson.
Outcome
A possible result of a chance process.
Probability
A number measuring how likely an event is.
Sample space
The set of all possible outcomes.

Interactive math lab

Change it. See it. Understand it.

Adjust the values and watch the relationship respond.

Live model
Quantity A6
÷
Quantity B3
=
Rate / ratio2
What the visual is showing
Quantity A6
Quantity B3
Rate / ratio2

Worked examples

See the idea in action.

Worked example 1An experiment has 7 equally likely outcomes and 2 favorable outcomes. What is the probability? → 2/7

Probability is favorable outcomes divided by total outcomes.

Worked example 2A coin is flipped twice. How many equally likely ordered outcomes are possible? → 4

The outcomes are HH, HT, TH, and TT.

Guided practice

20 questions drawn from a 150-question lesson bank.

Each practice session mixes the major skills in this lesson so you practice the whole topic, not just one repeated problem type.

Score0/100 checked
Question bank150per lesson
This lesson covers
Sample spaceSimple probabilityCompound eventsModelsApplications
Question 1 of 100% complete
Question 01Sample space
Choose one answer

When rolling one standard six-sided die, how many outcomes are in the sample space?

This question is checking: Sample space.
Want a different mix?

Curriculum reference

Built as a continuous K–12 progression.

The sequence follows widely used K–12 mathematics progressions and references the Common Core mathematics framework. Explanations, examples, interactive models, and practice questions are original FreeLearnHub material.

View mathematics standards ↗