If x and y are integers, is y even?(1) (x + 2) * (y2 + 7) is even(2) (...
Step 1 and 2: Understand the question and draw inferences
We are given that x and y are integers, and we are asked if y is even. Since we do not have any more information to draw inferences from, let’s move straight to Statement 1.
Step 3: Analyze Statement 1
(x + 2) * (y2 + 7) is even
The product of two numbers is even if at least one of the two numbers is even.
Thus, three possibilities arise:
Statement 1 holds true for each of these 3 cases. Thus, we cannot ascertain for sure if y is odd or even.
Therefore, Statement 1 alone is not sufficient to answer the question.
Step 4: Analyze Statement 2
(x3 + 8) * (y2 -4) is even
Again, the product of two numbers is even if at least one of the two numbers is even.
So, three possibilities arise for this statement as well:
Statement 2 holds true for each of these 3 cases. Thus, we cannot ascertain for sure if y is odd or even.
Therefore, Statement 2 alone is not sufficient to answer the question.
Step 5: Analyze both statements together (if needed)
We have seen that
Statement 1 holds true if:
i) x is even, y is even or odd
ii) x is odd, y is odd
Statement 2 holds true if:
i) x is even, y is even or odd
ii) x is odd, y is even
Both Statements will be true at the same time only if:
x is even, y is even or odd.
Thus, even after combining both the statements, we have not been able to ascertain the even-odd nature of y.
Thus, both the statements together are not sufficient to answer the question.
Correct Answer Choice: Option E