Question

Which is a counterexample to this conjecture? The sum of any two consecutive integers is a composite number. A. 16 + 17 = 33 B. 10 + 11 = 21 C. 6 + 7 = 13 D. 7 + 8 = 15

Answer 1

C. 6 + 7 = 13

This is because 33, 21, and 15 are composite numbers, and 13 is not.