23.5 Venn diagrams and set notation — Practise
Work through these independently. Every question gives you a chance to check what you understand.
- In 40 students, 22 study art, 17 study music and 8 study both. How many study neither?
- In a group of 25, 7 are in both sets A and B. Find for a random selection.
- There are 18 in A, 13 in B and 5 in both. Find the number in .
- Set A contains 20 people, including 6 who are also in B. How many are in A only?
- Of 30 people, 21 are in at least one of A or B. Find the probability a random person is in neither.
- What does mean?
- What does mean?
- In 32 people, 15 are in A, 14 are in B and 4 in both. Find the number in neither.
- Set B has 19 members, 8 of whom are also in A. Find the number in B only.
- In a group of 50, 31 belong to A or B. How many are outside both sets?
Answers and concise solutions
1. In 40 students, 22 study art, 17 study music and 8 study both. How many study neither?
Answer: .
2. In a group of 25, 7 are in both sets A and B. Find for a random selection.
Answer: .
3. There are 18 in A, 13 in B and 5 in both. Find the number in .
Answer: .
4. Set A contains 20 people, including 6 who are also in B. How many are in A only?
Answer: .
5. Of 30 people, 21 are in at least one of A or B. Find the probability a random person is in neither.
Answer: .
6. What does mean?
Answer: It means in both A and B.
7. What does mean?
Answer: It means in A or B or both.
8. In 32 people, 15 are in A, 14 are in B and 4 in both. Find the number in neither.
Answer: .
9. Set B has 19 members, 8 of whom are also in A. Find the number in B only.
Answer: .
10. In a group of 50, 31 belong to A or B. How many are outside both sets?
Answer: .