Number theoryDifficulty 1.0Find the answerUKMT Senior Mathematical Challenge · United Kingdom · 2016
Which of the following values of the positive integer n is a counterexample to the statement: "If n is not prime then n−2 is not prime"?
(A) 6 (B) 11 (C) 27 (D) 33 (E) 51
The source for this one didn't record the answer, so there is nothing to check what you type against. Work it on paper and mark yourself against the solution below.