BTGModeratorVI wrote: ↑Tue Mar 31, 2020 5:14 am
If x is an integer, is x odd?
(1) x + 4 is an odd integer.
(2) x/3 is NOT an even integer.
Answer:
A
Source: Kaplan
Target question: Is x odd?
Some important rules:
1. ODD + ODD = EVEN
2. ODD + EVEN = ODD
3. EVEN + EVEN = EVEN
Statement 1: x + 4 is an odd integer.
Since 4 is EVEN, we have: x + EVEN = ODD
From
rule #2 above, we can see that
x must be odd
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: x/3 is NOT an even integer.
There are several values of x that satisfy statement 2. Here are two:
Case a: x = 3. Here, x/3 = 3/3 = 1, and 1 is NOT an even integer. In this case,
x IS odd
Case b: x = 4. Here, x/3 = 4/3 = 1.333333...., and 1.333333.... is NOT an even integer. In this case,
x is NOT odd
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
