P(A or B) = P(A) + P(B): Problem Solving & Reasoning
Mathematics
Grade 7
15 questions
~30 mins
1 views0 downloads
About This Worksheet
A worksheet exploring the concept that for mutually exclusive events, P(A or B) = P(A) + P(B). Includes practice, problem solving, real-world scenarios, and advanced questions.
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P(A or B) = P(A) + P(B): Problem Solving & Reasoning
Subject: MathematicsGrade: Grade 7
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Untitled Worksheet
Grade Grade 7
A
Introduction
Read the explanation below to understand the key concept.
1.
The probability that event A occurs is P(A), and the probability that event B occurs is P(B). When A and B are mutually exclusive, the probability that either A or B occurs, written as P(A or B), is equal to P(A) + P(B).
[2 marks]2.
State the formula for P(A or B) when events A and B are mutually exclusive.
[2 marks]B
Fluency & Practice
Answer the following procedural questions to practice applying the formula.
1.
If P(A) = 0.3 and P(B) = 0.4, find P(A or B) assuming A and B are mutually exclusive.
[3 marks]2.
Given P(A) = 0.2 and P(B) = 0.5, calculate P(A or B).
[2 marks]3.
If P(A or B) = 0.6, P(A) = 0.25, and P(B) = 0.30, are A and B mutually exclusive? Show your reasoning.
[4 marks]C
Target Level Practice
Solve these questions that require applying the concept to different contexts.
1.
In a class, 40% students like apples, and 30% like oranges. If students who like apples and oranges are mutually exclusive, what is the probability that a student likes either apples or oranges?
[3 marks]2.
A die is rolled. Event A: rolling an even number. Event B: rolling a number greater than 4. Are A and B mutually exclusive? Use probability to justify your answer.
[4 marks]3.
If P(A) = 0.15, P(B) = 0.25, and P(A or B) = 0.4, determine whether A and B are mutually exclusive.
[3 marks]4.
A bag contains red and blue balls. The probability of drawing a red ball is 0.3, and the probability of drawing a blue ball is 0.5. Assuming the events are mutually exclusive, what is the probability of drawing either a red or blue ball?
[3 marks]D
Challenge & Extension
Tackle these more advanced problems involving the concept.
1.
Events A and B are mutually exclusive with P(A) = 0.2 and P(B) = 0.35. Find P(A or B).
[3 marks]2.
If P(A) = 0.4, P(B) = 0.1, and P(A or B) = 0.45, explain why A and B are or are not mutually exclusive. Show your reasoning.
[4 marks]E
Mixed Review
Answer these varied questions to review the concept.
1.
Calculate P(A or B) if P(A) = 0.3, P(B) = 0.4, and they are mutually exclusive.
[2 marks]2.
Describe a real-world scenario where two events are mutually exclusive and apply the formula for P(A or B).
[4 marks]F
Error Analysis
Identify and correct the mistake in these statements.
1.
A student says: 'If P(A) = 0.4 and P(B) = 0.3, then P(A or B) = 0.7 regardless of whether the events are mutually exclusive.' Is this correct? Explain why or why not.
[3 marks]2.
A teacher states: 'Since the probability of event A is 0.6 and event B is 0.3, the probability of either happening is 0.9, so they must be mutually exclusive.' Is this correct? Why or why not?
[3 marks]Quick Actions
What is Remix?
Create a new worksheet based on this one. Change the grade level, topic, number of questions, or difficulty - then generate a fresh version.
- • Change grade level (Grade 6 → Grade 7)
- • Swap topics (Harry Potter → Macbeth)
- • Add more questions (10 → 15)
- • Adjust difficulty
Details
- Created
- 1/1/2026
- Updated
- 1/1/2026
- Type
- worksheet