The Venn diagram shows every element of the universal set U and of the sets A and B. Find |(A − B) ∪ (B ∩ A)|, the number of elements of (A − B) ∪ (B ∩ A).
Sets, relations & functions worksheet with answers
1.Easy
A = {10, 15, 18}B = {3, 5, 9, 10, 14, 18}|U| = 10
|(A − B) ∪ (B ∩ A)| =
2.Easy
How many subsets with exactly 2 elements does A = {1, 2, 3, 4} have? Call the number N.
A = {1, 2, 3, 4}
N =
3.Medium
Each number in the Venn diagram is the number of elements in that region. Find |(C ∩ B′)′|.
|U| = 59
|(C ∩ B′)′| =
4.Medium
Exactly one region of the Venn diagram is the set (C ∩ B) − (A ∩ B). Click its number.
(C ∩ B) − (A ∩ B)
- 1region 1
- 2region 2
- 3region 3
- 4region 4
- 5region 5
- 6region 6
- 7region 7
- 8region 8
5.Hard
The functions f and g on {1, 2, 3, 4, 5} are given by their tables. Find (f ∘ f)(5).
f: 1 ↦ 2, 2 ↦ 2, 3 ↦ 4, 4 ↦ 2, 5 ↦ 1g: 1 ↦ 3, 2 ↦ 3, 3 ↦ 2, 4 ↦ 3, 5 ↦ 5
(f ∘ f)(5) =
6.Hard
The arrow diagram shows a function f: A → B with A = {1, 2, 3} and B = {a, b, c}. Click the description that fits f.
f = {(1, c), (2, b), (3, a)}
- 1injective, not surjective
- 2surjective, not injective
- 3bijective
- 4neither
Answer key
- 1. |(A − B) ∪ (B ∩ A)| = 3
- 2. N = 6
- 3. |(C ∩ B′)′| = 40
- 4. region 6
- 5. (f ∘ f)(5) = 2
- 6. bijective
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