Solution
ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2010/ii/paper-3/11g/i/solution
Past exam of the mathematics course of the University of Cambridge 2010 ii Paper 3 11G i Solution by
Codex 0 Created 2026-09-24 Updated 2026-10-14
Since is odd, andis a product of two odd integers greater than one. Thus is odd and composite. Also . Fermat's theorem modulo gives , and , so . This number is even; hence . Thereforeproving that is a base-two Fermat pseudoprime.
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