Gmat_mission wrote: ↑Thu May 21, 2020 1:21 am
If \(n + k = m,\) what is the value of \(k ?\)
(1) \(n = 10\)
(2) \(m + 10 = n\)
[spoiler]OA=B[/spoiler]
Source: Official Guide
Here's one approach...
Target question: What is the value of k?
Given: n + k = m
Statement 1: n = 10
Let's TEST some values
There are several values of m, n and k that satisfy statement 1. Here are two:
Case a:
m = 12, n = 10, and k = 2. So, we have
10 + 2 = 12. In this case,
k = 2
Case b:
m = 13, n = 10, and k = 3. So, we have
10 + 3 = 13. In this case,
k = 3
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: m + 10 = n
Take: m + 10 = n
Subtract 10 from both sides to get: m = n - 10
Rewrite as: m = n + (-10)
Rewrite as: n + (-10) = m
Add some color:
n + (-10) = m
Compare this to the given information:
n + k = m
From this, it is clear that
k = -10
Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
