[計量]GWD30-Q13

[qwersony (耍人)]

Q13:
If x + y is an integer, is y an integer?
(1)       x – y is an integer.
(2)       x + 2y is an integer.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is
sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.


答案是B

WHY?

(X,Y) 不有可能也是 (1/3,1/3) or (整數,整數)嗎?


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◆ From: 58.114.189.97
推 scuhans:X+Y是整數阿(題幹)  1/3+1/3 不是整數
→ scuhans:X+Y是整數(a)   X+2Y是整數(b)
→ scuhans:(b)-(a) y=整數
→ qwersony:THANK YOU~~