coolmrityu wrote:Is the integer x even?
(1) x^2 is an even integer.
(2) x/4 is an odd integer.
Target question:
Is the integer x even?
Statement 1: x^2 is an even integer.
If (x)(x) is even, then it
must be the case that
x is even
To demonstrate this, consider the following rules:
(odd)(odd) = odd
(odd)(even) = even
(even)(even) = even
So, if the product of two integers is even, then it must be the case that
either both numbers are even
or one is odd and one is even.
Since, x^2 requires us to multiply x by itself, we can rule out the possibility of one number being odd and the other number being even. This means that both numbers (x and x) are even.
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: x/4 is an odd integer.
We need only focus on the part that says, x/4 is an integer.
Let's say that x/4 = k (where k is an integer)
This means that x = 4k
In other words, x = (2)(2)k, which means x is a multiple of 2, which means
x is definitely even
Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer =
D
Cheers,
Brent
