The question is from Official Guide (12th), page 282, Q 106
If x and y are integers, is xy even?
(1) x = y+1
(2) x/y is an even integer.
Clearly we need to find if either x or y is an even. It's pretty obviously that (2) is sufficient since x is an even.
For (1), I disagree that the answer. The answer says it's a sufficient statement, because this equation provides that x and y are consecutive integers, so either x or y is even. However, what if y=0 and x=1? Their product is not even in that case. I don't think (1) is sufficient.
Let me know what you think.
If x and y are integers, is xy even?
(1) x = y+1
(2) x/y is an even integer.
Clearly we need to find if either x or y is an even. It's pretty obviously that (2) is sufficient since x is an even.
For (1), I disagree that the answer. The answer says it's a sufficient statement, because this equation provides that x and y are consecutive integers, so either x or y is even. However, what if y=0 and x=1? Their product is not even in that case. I don't think (1) is sufficient.
Let me know what you think.
