Practice Set in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

A well-defined collection of distinct, unordered objects called elements, described either by listing or by a membership rule.

Think of a set as a bag that can hold anything — numbers, names, shapes — but with two strict rules: no duplicates allowed and the order in which items sit inside the bag does not matter.

Showing a random 20 of 50 problems.

Example 1

medium
Write {x∈Z:x divides 6} in roster form (positive divisors only).

Example 2

medium
Set A is described as 'all integers x with x2=9'. List A by roster.

Example 3

medium
Write {x∈Z:x2=9} in roster form.

Example 4

easy
Is {3} the same thing as the number 3?

Example 5

hard
How many subsets does a set with 5 elements have?

Example 6

easy
True or false: the set of letters in 'EYE' has 3 elements.

Example 7

challenge
Prove that if sets A and B satisfy A⊆B and B⊆A, then A=B.

Example 8

easy
Is {1,2,3} the same set as {3,2,1}?

Example 9

challenge
Set S contains its own number of elements rule: S={1,2,…,n} has exactly n elements. If a set T satisfies ∣T∣=∣T∪{5}∣, what must be true about 5?

Example 10

medium
List the subset of {1,2,3,4,5,6,7,8,9,10} consisting of perfect squares.

Example 11

easy
Let C={a,e,i,o,u}. List all elements of C and state the cardinality ∣C∣.

Example 12

easy
Let A={2,4,6,8,10}. Determine whether 6∈A and whether 5∈A.

Example 13

medium
Write the set B={x∈Z:−2≤x<3} in roster notation.

Example 14

medium
Convert {x∈Z:1≤x≤6 and x is odd} to roster form.

Example 15

medium
True or false: {1,2,3} has the same elements as {2,3,1,2}.

Example 16

easy
Is {1,2}={1,2,3}?

Example 17

easy
Are the sets {2,4,4,6} and {6,2,4} equal? Explain.

Example 18

easy
Let A={0,1,2,3}. Is 0∈A? Is −1∈A?

Example 19

medium
Are the sets {x:x is even} and {2k:k∈Z} equal?

Example 20

medium
Is the collection of 'the three best movies ever' a well-defined set?