ktrout2020 wrote:If mn ≠0, is m > n?
(1) 1/m < 1/n
(2) m² > n²
Target question: Is m > n?
Given: mn ≠0
Statement 1: 1/m < 1/n
This statement doesn't FEEL sufficient, so I'll TEST some values.
There are several values of m and n that satisfy statement 1. Here are two:
Case a: m = 2 and n = 1. In this case
m > n
Case b: m = -3 and n = 1. In this case
m < n
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Aside: For more on this idea of plugging in values when a statement doesn't feel sufficient, read my article: https://www.gmatprepnow.com/articles/dat ... lug-values
Statement 2: m² > n²
Before I start choosing numbers to test, I'll see if I can REUSE my numbers from statement 1.
Yes I can! Those same values satisfy the conditions in statement 2.
Case a: m = 2 and n = 1. In this case
m > n
Case b: m = -3 and n = 1. In this case
m < n
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
IMPORTANT: Notice that I was able to use the
same counter-examples to show that each statement ALONE is not sufficient. So, the same counter-examples will satisfy the two statements COMBINED.
In other words,
Case a: m = 2 and n = 1. In this case
m > n
Case b: m = -3 and n = 1. In this case
m < n
Since we cannot answer the
target question with certainty, the combined statements are NOT SUFFICIENT
Answer: A
Cheers,
Brent
