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2016 AMC 12A Problem 5

Problem 5 of 25Easier

Goldbach’s conjecture states that every even integer greater than 22 can be written as the sum of two prime numbers (for example, 2016=13+20032016=13+2003). So far, no one has been able to prove that the conjecture is true, and no one has found a counterexample to show that the conjecture is false. What would a counterexample consist of?

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Solution

A counterexample must satisfy the hypothesis of being an even integer greater than 22 while failing the conclusion that it can be written as the sum of two prime numbers. Thus, the correct answer is E.

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Concepts: counterexample · logical deduction

Problem text and solution from the LIVE past-contest archive. See also the AoPS wiki page for community solutions.