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1.1 Proof

1.1 Proof

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Question 17
a.

Ravi claims that 2n−12^n - 12n−1 is prime for every integer n⩾2n \geqslant 2n⩾2. Disprove Ravi's claim.

[2]
b.

Sian claims that if n2 n^2\,n2 is a multiple of 4 then n n\,n must be a multiple of 4. Disprove Sian's claim.

[2]
Markscheme

1.1 Proof Questions

  1. A Level
  2. /Maths
  3. /1.1 Proof

132 exam-style questions on OCR (MEI) A Level Maths 1.1 Proof, covering 1.1.1 Structure of mathematical proof, 1.1.2 Disproof by counter example, 1.1.3 Proof by contradiction (A-level only), and 1.1 Proof. Each one has a worked solution and a mark scheme showing where the marks go.

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