The Venn diagram shows every element of the universal set U and of the sets A and B. Find |B − A|, the number of elements of B − A.
Sets, relations & functions worksheet with answers
1.Easy
A = {3, 5, 13, 19}B = {10, 13}|U| = 8
|B − A| =
2.Easy
Exactly one region of the Venn diagram is the set A − B′. Click its number.
A − B′
- 1region 1
- 2region 2
- 3region 3
- 4region 4
3.Medium
The relation R on {1, 2, 3} is drawn as a directed graph (a loop means (x, x) ∈ R). Exactly one of the four properties holds. Click it.
R = {(1, 3), (3, 1), (3, 3)}
- 1reflexive
- 2symmetric
- 3antisymmetric
- 4transitive
4.Medium
Each number in the Venn diagram is the number of elements in that region. Find |(B ∩ A) − (B′ ∩ C)|.
|U| = 73
|(B ∩ A) − (B′ ∩ C)| =
5.Hard
The functions f and g on {1, 2, 3, 4, 5} are given by their tables. Find (g ∘ f)(5).
f: 1 ↦ 3, 2 ↦ 3, 3 ↦ 1, 4 ↦ 4, 5 ↦ 2g: 1 ↦ 2, 2 ↦ 3, 3 ↦ 1, 4 ↦ 4, 5 ↦ 4
(g ∘ 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, c), (3, c)}
- 1injective, not surjective
- 2surjective, not injective
- 3bijective
- 4neither
Answer key
- 1. |B − A| = 1
- 2. region 4
- 3. symmetric
- 4. |(B ∩ A) − (B′ ∩ C)| = 13
- 5. (g ∘ f)(5) = 3
- 6. neither
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