ReasoningAges 13-15

Sample space probability

Express the theoretical probability of a favourable event as a simplified fraction. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 13-15

Sample space probability

Take your time. Show your thinking.

1. A bag contains 5 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5 · 9 · Sample space probability
2. A bag contains 6 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
6 · 9 · Sample space probability
3. A bag contains 7 red marbles and 10 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
7 · 10 · Sample space probability
4. A bag contains 1 red marbles and 1 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1 · 1 · Sample space probability
5. A bag contains 4 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
4 · 9 · Sample space probability
6. A bag contains 7 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
7 · 7 · Sample space probability
7. A bag contains 12 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
12 · 7 · Sample space probability
8. A bag contains 10 red marbles and 11 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10 · 11 · Sample space probability
9. A bag contains 5 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5 · 7 · Sample space probability
10. A bag contains 10 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10 · 9 · Sample space probability
11. A bag contains 9 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
9 · 7 · Sample space probability
12. A bag contains 12 red marbles and 12 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
12 · 12 · Sample space probability

12 questions · Seed 55 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

Sample space probability

Answers and reasoning. Review before teaching.

1. A bag contains 5 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5/14
There are 5 red marbles out of 14 total marbles. Simplifying 5/14 by dividing by 1 gives 5/14.
2. A bag contains 6 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
2/5
There are 6 red marbles out of 15 total marbles. Simplifying 6/15 by dividing by 3 gives 2/5.
3. A bag contains 7 red marbles and 10 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
7/17
There are 7 red marbles out of 17 total marbles. Simplifying 7/17 by dividing by 1 gives 7/17.
4. A bag contains 1 red marbles and 1 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1/2
There are 1 red marbles out of 2 total marbles. Simplifying 1/2 by dividing by 1 gives 1/2.
5. A bag contains 4 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
4/13
There are 4 red marbles out of 13 total marbles. Simplifying 4/13 by dividing by 1 gives 4/13.
6. A bag contains 7 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1/2
There are 7 red marbles out of 14 total marbles. Simplifying 7/14 by dividing by 7 gives 1/2.
7. A bag contains 12 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
12/19
There are 12 red marbles out of 19 total marbles. Simplifying 12/19 by dividing by 1 gives 12/19.
8. A bag contains 10 red marbles and 11 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10/21
There are 10 red marbles out of 21 total marbles. Simplifying 10/21 by dividing by 1 gives 10/21.
9. A bag contains 5 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5/12
There are 5 red marbles out of 12 total marbles. Simplifying 5/12 by dividing by 1 gives 5/12.
10. A bag contains 10 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10/19
There are 10 red marbles out of 19 total marbles. Simplifying 10/19 by dividing by 1 gives 10/19.
11. A bag contains 9 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
9/16
There are 9 red marbles out of 16 total marbles. Simplifying 9/16 by dividing by 1 gives 9/16.
12. A bag contains 12 red marbles and 12 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1/2
There are 12 red marbles out of 24 total marbles. Simplifying 12/24 by dividing by 12 gives 1/2.

12 questions · Seed 55 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Sample space probability

Take your time. Show your thinking.

1. A bag contains 5 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5 · 9 · Sample space probability
2. A bag contains 6 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
6 · 9 · Sample space probability
3. A bag contains 7 red marbles and 10 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
7 · 10 · Sample space probability
4. A bag contains 1 red marbles and 1 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1 · 1 · Sample space probability
5. A bag contains 4 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
4 · 9 · Sample space probability
6. A bag contains 7 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
7 · 7 · Sample space probability
7. A bag contains 12 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
12 · 7 · Sample space probability
8. A bag contains 10 red marbles and 11 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10 · 11 · Sample space probability
9. A bag contains 5 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5 · 7 · Sample space probability
10. A bag contains 10 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10 · 9 · Sample space probability
11. A bag contains 9 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
9 · 7 · Sample space probability
12. A bag contains 12 red marbles and 12 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
12 · 12 · Sample space probability

12 questions · Seed 55 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Sample space probability

Answers and reasoning. Review before teaching.

1. A bag contains 5 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5/14
There are 5 red marbles out of 14 total marbles. Simplifying 5/14 by dividing by 1 gives 5/14.
2. A bag contains 6 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
2/5
There are 6 red marbles out of 15 total marbles. Simplifying 6/15 by dividing by 3 gives 2/5.
3. A bag contains 7 red marbles and 10 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
7/17
There are 7 red marbles out of 17 total marbles. Simplifying 7/17 by dividing by 1 gives 7/17.
4. A bag contains 1 red marbles and 1 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1/2
There are 1 red marbles out of 2 total marbles. Simplifying 1/2 by dividing by 1 gives 1/2.
5. A bag contains 4 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
4/13
There are 4 red marbles out of 13 total marbles. Simplifying 4/13 by dividing by 1 gives 4/13.
6. A bag contains 7 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1/2
There are 7 red marbles out of 14 total marbles. Simplifying 7/14 by dividing by 7 gives 1/2.
7. A bag contains 12 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
12/19
There are 12 red marbles out of 19 total marbles. Simplifying 12/19 by dividing by 1 gives 12/19.
8. A bag contains 10 red marbles and 11 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10/21
There are 10 red marbles out of 21 total marbles. Simplifying 10/21 by dividing by 1 gives 10/21.
9. A bag contains 5 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
5/12
There are 5 red marbles out of 12 total marbles. Simplifying 5/12 by dividing by 1 gives 5/12.
10. A bag contains 10 red marbles and 9 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
10/19
There are 10 red marbles out of 19 total marbles. Simplifying 10/19 by dividing by 1 gives 10/19.
11. A bag contains 9 red marbles and 7 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
9/16
There are 9 red marbles out of 16 total marbles. Simplifying 9/16 by dividing by 1 gives 9/16.
12. A bag contains 12 red marbles and 12 blue marbles. What is the probability of picking a red marble at random, written as a simplified fraction?
1/2
There are 12 red marbles out of 24 total marbles. Simplifying 12/24 by dividing by 12 gives 1/2.

12 questions · Seed 55 · Age guidance, not curriculum certification