Learning pack · Foundation · CIE Core

Probability

What's in this pack: printable worksheet PDF, matching answers PDF (Foundation · CIE Core depth). Probability measures likelihood from 0 to 1. Listing outcomes carefully and using fractions in lowest terms keeps marks safe.

Resources at the top · full summary · videos with short notes below.

🎒 Resources in this pack

Jump straight to the printable files, or scroll to the summary and videos.

Scaffolded Learning Sheet — attempt the worksheet, then use the Answers for a full written solution.

📝 Open Learning Sheet ✅ Open answers 🎬 More topic videos (6)📖 Full summary

Files: foundation-12 Probability handout.pdf · foundation-12 Probability handout answers.pdf

Full topic summary

Probability measures likelihood from 0 to 1. Listing outcomes carefully and using fractions in lowest terms keeps marks safe.

Key learning points

Theoretical probability = favourable ÷ equally likely outcomes.
Probabilities of mutually exclusive exhaustive events sum to 1.
And/or language: multiply along a branch for AND; add for mutually exclusive OR.

Worked example 1 — Simple probability

Fair die. $P(\text{prime})$ ?

Working

P=\tfrac{3}{6}=\tfrac{1}{2}

Primes: 2, 3, 5.

Worked example 2 — Complement

If $P(A)=0.35$ , find $P(A')$ .

Working

P(A')=1-0.35=0.65

Complementary probabilities sum to 1.

Worked example 3 — Independent events

Two fair coins. $P(\text{two heads})$ ?

Working

\tfrac{1}{2}\times\tfrac{1}{2}=\tfrac{1}{4}

Multiply independent probabilities.

🎬 Topic videos

Probability Fundamentals (1 of 2: Diagrams, the Product Rule)
Eddie Woo · 6 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Mode & Median of a Continuous Probability Distribution
Eddie Woo · 8 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Fair Dice (Part 1)
Numberphile · 13 min
What makes a die fair? Links sample space, equally likely outcomes, and fairness.
Monty Hall Problem (best explanation)
Numberphile · 4 min
Clearer follow-up explanation of Monty Hall. Use after the short starter version.
Binomial distributions | Probabilities of probabilities, part 1
3Blue1Brown · 13 min
Classroom-ready explain of probability. Use when teaching this topic in Lower Secondary / IGCSE.
Why “probability of 0” does not mean “impossible” | Probabilities of probabilities, part 2
3Blue1Brown · 10 min
Classroom-ready explain of probability. Use when teaching this topic in Lower Secondary / IGCSE.

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Browse the hub Learning Packs & Summary, or open the compact Probability summary.