Probability of Mutually Exclusive Events — Interactive Lesson & Worksheet (Ages 14–16)

Can these two events happen at the same time? This 18-slide interactive lesson teaches mutually exclusive events and the addition law, one clear step at a time.

Understanding Mutually Exclusive Events at GCSE

Students learn that two events are mutually exclusive when they cannot happen at the same time, so the probabilities can be added: P(A or B) = P(A) + P(B). Worked examples include a coin landing on heads or tails, cards showing a square or a triangle, and a team winning or drawing. They also learn that the probabilities of an exhaustive set of mutually exclusive events add up to 1, so if the chance of rain is 0.92 the chance of no rain is 0.08.

What’s Included

• 18-slide interactive lesson on mutually exclusive events
• Learning objectives on mutually exclusive events, probabilities adding to 1 and the addition law
• A starter on finding the probability of an event not happening
• Worked examples with coins, cards and match results
• A printable worksheet with two question pages and an answer page

Key Benefits for Students

• Makes it clear when probabilities can be added
• Links the addition law to probabilities summing to 1
• Shows which events are and are not mutually exclusive
• Instant feedback on answer questions

Why Teachers Love It

• No prep — ready for whole-class teaching on an interactive whiteboard
• The worksheet gives ready-made practice with answers
• Self-marking questions support independent practice
• Suits teaching, revision and homework
• Familiar contexts keep examples accessible

Love this? You’ll love…

• Probability and Independent Events — Interactive Lesson & Worksheet (Ages 14–16)
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A dependable addition to a GCSE probability topic, giving students a clear rule for combining events. Confidence here leads naturally into independent events and conditional probability.

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FAQ

What year group is this for? Years 10–11 (ages 14–16), GCSE.

Is a worksheet included? Yes — two question pages and an answer page.

Do the probabilities of exclusive events add up to 1? Yes, for an exhaustive set — the lesson explains why.