Counterexamples Quizzes, Questions & Answers

Top Trending Counterexamples Quizzes

Advanced Counterexamples in Algebra, Logic, and Real Analysis

In this quiz, you’ll explore how counterexamples reveal hidden flaws in statements about infinity, equations, and logical implications. You’ll test claims like “every set is finite,” “all rational...

Questions: 15 | Attempts: 12 | Last updated: Jan 28, 2026

Sample Question 1
Counterexample to "Every set is finite":

{1,2,3}

{a,b}

Natural numbers

Empty set

Sample Question 2
Which disproves "All rational numbers are integers"?

2

−3

1/2

0

Sample Question 3
Counterexample to "For all x, sin(x) = x":

X = 0

X = π

X = 2π

X = π/2

Recent Counterexamples Quizzes

Counterexamples in Sets, Conditionals, and Everyday Statements

Questions: 15 | Attempts: 11 | Last updated: Jan 28, 2026

Sample Question
Counterexample to "All subsets are proper":

Empty subset

Singleton

Power set

The set itself

Counterexamples in Number Theory, Geometry, and Functions

Questions: 15 | Attempts: 11 | Last updated: Jan 28, 2026

Sample Question
Counterexample to "All triangles have equal sides":

Square

Circle

Scalene

Equilateral

Basics of Counterexamples and Disproving Universal Statements

Questions: 15 | Attempts: 11 | Last updated: Jan 28, 2026

Sample Question
What is the purpose of a counterexample?

To disprove a universal statement

To simplify a proof

To prove an existential statement

To prove a statement is true