天山3-27

knight9514

Q27:
If x and z are integers, is at least one of them even?
(1) x + z is odd.
(2) x - z is odd.
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.

0是Integer，算EVEN？OR ODD？

lololo

條件1看﹕ 當N是奇數﹐例如1﹐N=5 ﹐代入X=5 ﹐3的N次密(打不出那個MI字﹐抱歉
)循環規律為3。9。7。1﹐那3^5個位數就是3﹐3+1/10 余數為4﹔當N是偶數﹐例如
N=4﹐ X=16﹐3^16的尾數是9﹐9+1=10 ﹐所以條件 不確定是否能余數為0。

條件2﹐x> 4 同樣也有不同的情況出現﹐也不能確定。