A student named Elena makes the claim that there is a finite set of prime numbers P={p1,p2,p3,…,pk}P = \{p_1, p_2, p_3, \dots, p_k\}P={p1,p2,p3,…,pk} where pk p_k\,pk is the largest prime. Use the method of proof by contradiction to show that Elena's claim is incorrect, and thus prove that there are infinitely many prime numbers.
107 exam-style questions on Edexcel A Level Maths 1.1 Proof by Contradiction. Each one has a worked solution and a mark scheme showing where the marks go.