ReasoningAges 13-15

Conditional probability tables

Calculate conditional probability from subgroup counts and express the result as a simplified fraction. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 13-15

Conditional probability tables

Take your time. Show your thinking.

1. In a club, 14 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
14 s · 2 · Conditional probability ta…
2. In a club, 19 students play chess, and 12 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
19 s · 12 · Conditional probability ta…
3. In a club, 11 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
11 s · 3 · Conditional probability ta…
4. In a club, 30 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
30 s · 15 · Conditional probability ta…
5. In a club, 15 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
15 s · 6 · Conditional probability ta…
6. In a club, 10 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
10 s · 2 · Conditional probability ta…
7. In a club, 20 students play chess, and 13 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
20 s · 13 · Conditional probability ta…
8. In a club, 10 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
10 s · 6 · Conditional probability ta…
9. In a club, 10 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
10 s · 3 · Conditional probability ta…
10. In a club, 9 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
9 s · 6 · Conditional probability ta…
11. In a club, 22 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
22 s · 15 · Conditional probability ta…
12. In a club, 13 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
13 s · 2 · Conditional probability ta…

12 questions · Seed 104737 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

Conditional probability tables

Answers and reasoning. Review before teaching.

1. In a club, 14 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
1/7
Out of 14 chess players, 2 play an instrument. Simplifying 2/14 by dividing by 2 gives 1/7.
2. In a club, 19 students play chess, and 12 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
12/19
Out of 19 chess players, 12 play an instrument. Simplifying 12/19 by dividing by 1 gives 12/19.
3. In a club, 11 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
3/11
Out of 11 chess players, 3 play an instrument. Simplifying 3/11 by dividing by 1 gives 3/11.
4. In a club, 30 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
1/2
Out of 30 chess players, 15 play an instrument. Simplifying 15/30 by dividing by 15 gives 1/2.
5. In a club, 15 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
2/5
Out of 15 chess players, 6 play an instrument. Simplifying 6/15 by dividing by 3 gives 2/5.
6. In a club, 10 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
1/5
Out of 10 chess players, 2 play an instrument. Simplifying 2/10 by dividing by 2 gives 1/5.
7. In a club, 20 students play chess, and 13 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
13/20
Out of 20 chess players, 13 play an instrument. Simplifying 13/20 by dividing by 1 gives 13/20.
8. In a club, 10 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
3/5
Out of 10 chess players, 6 play an instrument. Simplifying 6/10 by dividing by 2 gives 3/5.
9. In a club, 10 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
3/10
Out of 10 chess players, 3 play an instrument. Simplifying 3/10 by dividing by 1 gives 3/10.
10. In a club, 9 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
2/3
Out of 9 chess players, 6 play an instrument. Simplifying 6/9 by dividing by 3 gives 2/3.
11. In a club, 22 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
15/22
Out of 22 chess players, 15 play an instrument. Simplifying 15/22 by dividing by 1 gives 15/22.
12. In a club, 13 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
2/13
Out of 13 chess players, 2 play an instrument. Simplifying 2/13 by dividing by 1 gives 2/13.

12 questions · Seed 104737 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Conditional probability tables

Take your time. Show your thinking.

1. In a club, 14 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
14 s · 2 · Conditional probability ta…
2. In a club, 19 students play chess, and 12 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
19 s · 12 · Conditional probability ta…
3. In a club, 11 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
11 s · 3 · Conditional probability ta…
4. In a club, 30 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
30 s · 15 · Conditional probability ta…
5. In a club, 15 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
15 s · 6 · Conditional probability ta…
6. In a club, 10 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
10 s · 2 · Conditional probability ta…
7. In a club, 20 students play chess, and 13 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
20 s · 13 · Conditional probability ta…
8. In a club, 10 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
10 s · 6 · Conditional probability ta…
9. In a club, 10 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
10 s · 3 · Conditional probability ta…
10. In a club, 9 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
9 s · 6 · Conditional probability ta…
11. In a club, 22 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
22 s · 15 · Conditional probability ta…
12. In a club, 13 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
13 s · 2 · Conditional probability ta…

12 questions · Seed 104737 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Conditional probability tables

Answers and reasoning. Review before teaching.

1. In a club, 14 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
1/7
Out of 14 chess players, 2 play an instrument. Simplifying 2/14 by dividing by 2 gives 1/7.
2. In a club, 19 students play chess, and 12 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
12/19
Out of 19 chess players, 12 play an instrument. Simplifying 12/19 by dividing by 1 gives 12/19.
3. In a club, 11 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
3/11
Out of 11 chess players, 3 play an instrument. Simplifying 3/11 by dividing by 1 gives 3/11.
4. In a club, 30 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
1/2
Out of 30 chess players, 15 play an instrument. Simplifying 15/30 by dividing by 15 gives 1/2.
5. In a club, 15 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
2/5
Out of 15 chess players, 6 play an instrument. Simplifying 6/15 by dividing by 3 gives 2/5.
6. In a club, 10 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
1/5
Out of 10 chess players, 2 play an instrument. Simplifying 2/10 by dividing by 2 gives 1/5.
7. In a club, 20 students play chess, and 13 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
13/20
Out of 20 chess players, 13 play an instrument. Simplifying 13/20 by dividing by 1 gives 13/20.
8. In a club, 10 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
3/5
Out of 10 chess players, 6 play an instrument. Simplifying 6/10 by dividing by 2 gives 3/5.
9. In a club, 10 students play chess, and 3 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
3/10
Out of 10 chess players, 3 play an instrument. Simplifying 3/10 by dividing by 1 gives 3/10.
10. In a club, 9 students play chess, and 6 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
2/3
Out of 9 chess players, 6 play an instrument. Simplifying 6/9 by dividing by 3 gives 2/3.
11. In a club, 22 students play chess, and 15 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
15/22
Out of 22 chess players, 15 play an instrument. Simplifying 15/22 by dividing by 1 gives 15/22.
12. In a club, 13 students play chess, and 2 of those chess players also play a musical instrument. Given that a student chosen at random plays chess, what is the conditional probability that they also play a musical instrument, as a simplified fraction?
2/13
Out of 13 chess players, 2 play an instrument. Simplifying 2/13 by dividing by 1 gives 2/13.

12 questions · Seed 104737 · Age guidance, not curriculum certification