1. Logic, Sets, and Proof

Direct Proof, Contradiction, Contrapositive — Quiz

Test your understanding of direct proof, contradiction, contrapositive with 5 practice questions.

Practice Questions

Question 1

In a direct proof of a statement of the form $P \implies Q$, what is the usual starting assumption?

Question 2

Which statement is the contrapositive of 'If an integer is divisible by $4$, then it is even'?

Question 3

What is the negation of the statement 'For every real number $x$, $x^2 \ge 0$'?

Question 4

Which description best matches a proof by contradiction?

Question 5

Which statement is logically equivalent to $P \implies Q$?