| Exam Board | AQA |
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| Module | AS Paper 1 (AS Paper 1) |
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| Year | 2019 |
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| Session | June |
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| Marks | 1 |
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| Topic | Proof |
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2 Dan believes that for every positive integer \(n\), at least one of \(2 ^ { n } - 1\) and \(2 ^ { n } + 1\) is prime.
Which value of \(n\) shown below is a counter example to Dan's belief?
Circle your answer.
[0pt]
[1 mark]
\(n = 3\)
\(n = 4\)
\(n = 5\)
\(n = 6\)