ProbabilityDeep Dive

Venn Diagram Applications

Part of Venn Diagrams · GCSE GCSE Mathematics revision

This deep dive covers Venn Diagram Applications within Venn Diagrams for GCSE Mathematics. Revise Venn Diagrams in Probability for GCSE Mathematics with 14 exam-style questions and 12 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 7 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 4 of 7

Practice

14 questions

Recall

12 flashcards

Venn Diagram Applications

Example 1: Survey Data

Problem: In a class of 30 students:

  • 18 students play football (F)
  • 12 students play tennis (T)
  • 8 students play both sports
Step-by-Step Solution:

Step 1: Start with the intersection (both)

Students who play both: 8

Step 2: Find "only" regions

Only football: 18 - 8 = 10

Only tennis: 12 - 8 = 4

Step 3: Find "neither"

Neither sport: 30 - (10 + 8 + 4) = 8

Step 4: Check total

Total: 10 + 8 + 4 + 8 = 30 ✓

Probability Calculations

Using the same example:

  • P(F) = 18/30 = 3/5
  • P(T) = 12/30 = 2/5
  • P(F ∩ T) = 8/30 = 4/15
  • P(F ∪ T) = 22/30 = 11/15
  • P(F') = 12/30 = 2/5

Key Formulas

Addition Rule: P(A ∪ B) = P(A) + P(B) - P(A ∩ B)

Complement Rule: P(A') = 1 - P(A)

Conditional Probability: P(A|B) = P(A ∩ B) / P(B)

Example 2: Conditional Probability

Using the sports example:

Find: P(plays tennis | plays football)

P(T|F) = P(T ∩ F) / P(F) = (8/30) / (18/30) = 8/18 = 4/9

Meaning: Of the students who play football, 4/9 also play tennis

Keep building this topic

Read this section alongside the surrounding pages in Venn Diagrams. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Venn Diagrams

In a Venn diagram with two events A and B, which symbol represents the region where BOTH events occur at the same time?

  • A. A ∩ B
  • B. A ∪ B
  • C. A'
  • D. U
1 markfoundation

A student claims: 'To find P(A ∪ B), you simply add P(A) and P(B).' Explain why this is not always correct, and state the correct formula with a reason.

3 markshigher

Quick Recall Flashcards

What does A ∪ B mean?
The union - outcomes where AT LEAST ONE of event A or event B occurs. Includes only A, only B, and A ∩ B. The ∪ symbol looks like a U for Union.
What does A ∩ B mean?
The intersection - outcomes where BOTH event A AND event B occur. On the diagram it is the overlapping region between the two circles.

14 questions on Venn Diagrams — practise free

Instant marking, adaptive difficulty, and 12 spaced repetition flashcards. Free until your GCSEs.

Try PrepWise Free