BTGModeratorVI wrote: ↑Sun Mar 15, 2020 12:46 pm
What is the value of x if x^3 < x^2?
(1) –2 < x < 2
(2) x is an integer greater than –2.
Answer:
B
Source: Official Guide
Target question: What is the value of x?
Given: x³ < x²
If we do a little bit of work, we'll see that this given information tells us A LOT about x
x² must be POSITIVE here (since we can see that
x ≠ 0, otherwise we can't have x³ < x²). So, we can safely divide both sides of the inequality by x² to get:
x < 1
So,
x < 1 AND x ≠ 0
Statement 1: –2< x < 2
There are several values of x that satisfy statement 1 (and the given information). Here are two:
Case a:
x = -1
Case b:
x = 0.5
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: x is an integer greater than –2
So, x is an INTEGER that's less than 1, but greater than -2 AND
x ≠ 0
There's only one x-value (
x = -1) that satisfies these conditions. So,
x must equal -1
Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
