BTGModeratorVI wrote: ↑Tue Feb 16, 2021 8:12 am
Is integer d even?
(1) d/4 is an odd integer.
(2) d - 3 is divisible by 5.
Answer:
A
Source: Princeton Review
Target question: Is integer d even?
Statement 1: d/4 is an odd integer.
All odd integers can be written in the form
2k + 1, where k is an integer
So we can rewrite statement 1 as follows: d/4 =
2k + 1
Multiply both sides of the equation by 4 to get: d = 8y + 4
Factor as follows: d =
2(4y + 2)
So, we can be certain that d is a multiple of
2, which means
d must be even
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: d - 3 is divisible by 5
There are several values of d that satisfy statement 2. Here are two:
Case a: d = 8. In this case, the answer to the target question is
YES, d is even
Case b: d =13. In this case, the answer to the target question is
NO, d is not even
Since we can’t answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
