College Math - Quiz 1 - Set Theory

Vocab Vault

100

What is the term for a collection of distinct objects?

A Ser

200

What is the symbol that means “is an element of”?

∈

300

What is the difference between a finite set and an infinite set?

A finite set has a countable number of elements; an infinite set has no end.

400

What is the name for a set with no elements?

The empty set or ∅

500

Give an example of two sets that are equivalent but not equal.

{1,2,3} and {a,b,c} — same number of elements, different elements.

Name that Set

100

8 belongs to…

N,W,Z,Q,R

200

0 belongs to…

W,Z,Q,R

300

-4 belongs to…

Z,Q,R

400

π (pi) belongs to…

R\Q (irrational) , R

500

Find a number in Q but not in Z.

1/2, 3/4, 0.3  — it’s a rational number but not an integer

Roster vs Builder

100

{1,2,3,4}

{x∣ x∈N , x≤4}

200

Odd natural numbers less than 12 (in set builder)

 {x∣ x∈N, x is odd , x<12}

300

{x | x ∈ ℕ, x ≤ 5}

{1, 2, 3, 4, 5}

400

{x | x ∈ ℤ, -4 ≤ x ≤ 4}

{-4, -3, -2, -1, 0, 1, 2, 3, 4}

500

{0,5,10,15,20}

{x∣ x∈W , x is a multiple of 5, x≤20}

Classifying

100

Equal, Equivalent, or Neither

{1,2,3} and {3,2,1}

Equal

200

Finite or Infinite

{1,2,3,4,5}

Finite

300

Equal, Equivalent, or Neither

{a, b, c, d, e} and {lions, tigers, bears, donkeys, fish}

Equivalent

400

Finite or Infinite

Set of all even integers

Infinite

500

Finite or Infinite

{x| x ∈  ℤ , -1,000,000 < x < 1,000,000}

Finite

Subset

100

Definition of a subset

A set that contains some but not all elements of another set;

200

Number of Proper subsets of {a,b}

→ Answer: 2^2 −1= 4 - 1 = 3 proper subsets

300

n(A) for {2,4,6,8,10}

5

400

A = {-100, -50, 0, 50, 100}

B = {-100 , 100}

___ ⊂ ___

B ⊂ A

500

A = {x| x ∈ W , x ≤ 7}

255