If n is an integer, which of the following must be even?
2 Explanations
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In a multiplication, the only way to get an odd solution is:
odd*odd
Since 2n is a multiplication in which, at least one of the terms is even (2), in the 100% of the cases the solution will be even. It does not matter if n is even or not, since:
even * even = even
even * odd = even
2n will ALWAYS be even (Notice that is a "must be" question, not a "could be" one, so the answer has to be even in all the possible autcomes).
2 Explanations