Data Sufficiency

VJesus12 wrote:If m and n are consecutive positive integers, is m greater than n?

(1) m-1 and n+1 are consecutive positive integers
(2) m is an even integer

[spoiler]OA=A[/spoiler]

Source: Official Guide

Given that m and n are consecutive positive integers, there are two possibilities: 1. m > n and 2. n > m.

We have to determine whether m > n.

Let's take each statement one by one.

(1) m - 1 and n + 1 are consecutive positive integers.

Case 1: Say m - 1 and n + 1 are consecutive positive integers, in that order.

Thus, m - 1 + 1 = n + 1 => m = n + 1. We see that m and n are consecutive positive integers and m > n.

Case 2: Say m - 1 and n + 1 are consecutive positive integers, in reverse order.

Thus, n + 1 + 1 = m - 1 => n + 3 = m. We see that m and n are NOT consecutive positive integers; thus, it is not a valid case, or only Case 1 is valid. Thus, m > n. Sufficient.

(2) m is an even integer.

Clearly insufficient.

The correct answer: A

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: Zurich GMAT Prep | Free ACT Practice Questions | LSAT Prep Courses Cambridge | SAT Prep Courses Shanghai | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.