Let A = {a, c} and B = {1, 2, 3, 4}. Find |𝒫(A)|.
Sets, relations & functions worksheet with answers
1.Easy
A = {a, c}B = {1, 2, 3, 4}
|𝒫(A)| =
2.Easy
Let A = {b, x} and B = {1, 2, 3, 4}. Find |A × B|.
A = {b, x}B = {1, 2, 3, 4}
|A × B| =
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, 1), (1, 2), (1, 3), (3, 1), (3, 2), (3, 3)}
- 1reflexive
- 2symmetric
- 3antisymmetric
- 4transitive
4.Medium
R = {(1, 3), (1, 4), (2, 1), (3, 1), (3, 2), (3, 3)} is a relation on {1, 2, 3, 4}. What is the smallest number k of ordered pairs that must be added to R to make it transitive (the size of the transitive closure minus |R|)?
R = {(1, 3), (1, 4), (2, 1), (3, 1), (3, 2), (3, 3)}
k =
5.Hard
The arrow diagram shows a function f: A → B with A = {1, 2, 3, 4} and B = {a, b, c, d}. Click the description that fits f.
f = {(1, c), (2, b), (3, a), (4, d)}
- 1injective, not surjective
- 2surjective, not injective
- 3bijective
- 4neither
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, b), (2, a), (3, b)}
- 1injective, not surjective
- 2surjective, not injective
- 3bijective
- 4neither
Answer key
- 1. |𝒫(A)| = 4
- 2. |A × B| = 8
- 3. transitive
- 4. k = 6
- 5. bijective
- 6. neither
Full step-by-step solutions: practise this topic on examproblems.com.