Source: Official Guide for the GMAT 13th Ed. Problem Solving; #44 Official Guide for the GMAT 2015 14th Ed. Problem Solving; #44

1

If n is an integer, which of

If n is an integer, which of the following must be even?

2 Explanations

1

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).

So, correct answer 2n (C).

Jan 25, 2015 • Comment

2

Gravatar Mike McGarry, Magoosh Tutor

Dec 27, 2013 • Comment

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Section 5.3 Problem Solving

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