About Probability Introduction — Class 6 IB

Describe likelihood of events using words and simple fractions through experiments. This topic is part of the IB Class 6 mathematics syllabus (chapter: Unit 9). On this page you can practice 60 questions across three difficulty levels — 20 easy, 20 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 35-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Probability Introduction — solved examples for Class 6 IB

Practice questions on Probability Introduction

1. Q1.easy

   What is the probability of rolling a 3 on a fair die?

   1. A)$\frac{1}{2}$
   2. B)$\frac{1}{3}$
   3. C)$\frac{1}{6}$
   4. D)$\frac{3}{6}$
   Show answer

   Answer: $\frac{1}{6}$

   Hint: A die has 6 faces.

2. Q2.easy

   An event that is certain to happen has a probability of:

   1. A)0
   2. B)$\frac{1}{2}$
   3. C)1
   4. D)2
   Show answer

   Answer: 1

   Hint: Certain means it will definitely happen.

3. Q3.easy

   A bag has 3 red and 5 blue marbles. What is the probability of picking a red marble?

   1. A)$\frac{3}{5}$
   2. B)$\frac{5}{8}$
   3. C)$\frac{3}{8}$
   4. D)$\frac{1}{3}$
   Show answer

   Answer: $\frac{3}{8}$

   Hint: Total marbles = 3 + 5 = 8.

4. Q4.medium

   A bag has 5 red, 4 blue, and 6 green balls. What is the probability of picking blue or green?

   1. A)$\frac{4}{15}$
   2. B)$\frac{6}{15}$
   3. C)$\frac{10}{15}$
   4. D)$\frac{2}{3}$
   Show answer

   Answer: $\frac{2}{3}$

   Hint: Blue or green = 4 + 6 = 10 out of 15.

5. Q5.medium

   A letter is chosen at random from PROBABILITY. What is the probability of choosing a vowel?

   1. A)$\frac{3}{11}$
   2. B)$\frac{4}{11}$
   3. C)$\frac{5}{11}$
   4. D)$\frac{6}{11}$
   Show answer

   Answer: $\frac{4}{11}$

   Hint: PROBABILITY has 11 letters. Count the vowels: O, A, I, I.

6. Q6.medium

   A die is rolled. What is the probability of getting a prime number?

   1. A)$\frac{1}{6}$
   2. B)$\frac{1}{3}$
   3. C)$\frac{1}{2}$
   4. D)$\frac{2}{3}$
   Show answer

   Answer: $\frac{1}{2}$

   Hint: Prime numbers on a die: 2, 3, 5.

7. Q7.hard

   A bag has 5 red and 3 blue marbles. Two are drawn without replacement. What is the probability both are red?

   1. A)$\frac{25}{64}$
   2. B)$\frac{5}{14}$
   3. C)$\frac{5}{8}$
   4. D)$\frac{10}{28}$
   Show answer

   Answer: $\frac{5}{14}$

   Hint: First: 5/8. Second (no replacement): 4/7.

8. Q8.hard

   The probability of event A is $\frac{2}{5}$ and event B is $\frac{1}{3}$. If A and B are independent, find P(A and B).

   1. A)$\frac{2}{15}$
   2. B)$\frac{3}{8}$
   3. C)$\frac{11}{15}$
   4. D)$\frac{1}{4}$
   Show answer

   Answer: $\frac{2}{15}$

   Hint: For independent events: P(A and B) = P(A) × P(B).

9. Q9.hard

   A spinner has 5 equal sections numbered 1-5. It is spun twice. What is the probability of getting 3 both times?

   1. A)$\frac{1}{5}$
   2. B)$\frac{2}{5}$
   3. C)$\frac{1}{10}$
   4. D)$\frac{1}{25}$
   Show answer

   Answer: $\frac{1}{25}$

   Hint: Independent spins: (1/5) × (1/5).

These are 9 of the 60 questions available for Probability Introduction. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.