Is X even?
1. (x+1) * (x-2) is even
2. (x-3) * (x+5) is odd
Please explain your answer.
1. (x+1) * (x-2) is even ---> x can be odd and even
2. (x-3) * (x+5) is odd ---> x has to be even only
nice. OA is B
i tend to be more comfortable with technical approaches.
Stem: Is X even?
1. shows products of two terms is even
this can only happen under 2 scenarios
a. e*o = e
b. e*e = e
(x+1) * (x-2) = E
under the first scenario:
x+1 must be even. This only occurs if x is odd.
x-2 must be odd. this only occurs if x is odd.
Therefore, X is odd.
under the second scenario:
]x+1 must be even. This only occurs if x is odd.
x-2 must be even. this occurs if X is even.
X is even or odd.
Therefore, A is insuff.
2. Same approach as 1.