Probability is one of 10 topics in the Grade 11 Mathematics CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Write down the addition rule for probability, P(A or B), in terms of P(A), P(B), and P(A and B).
Answer: P(AorB)=P(A)+P(B)-P(AandB) — The addition rule is P(A or B) = P(A) + P(B) - P(A and B).
Easy
2. On a Venn diagram, the overlapping region between two circles represents:
The intersection, A and B
The union, A or B
The complement of A
The entire sample space
Answer: The intersection, A and B — The overlapping region of two circles on a Venn diagram represents outcomes belonging to both events, the intersection A and B.
Medium
3. P(A) = 0.4, P(B) = 0.5, and P(A and B) = 0.15. Calculate P(A or B).
Answer: 0.75 — P(A or B) = P(A)+P(B)-P(A and B) = 0.4+0.5-0.15 = 0.75.
