扫描二维码，直接登录
题库 / GMATAdvanced-DS-74
If x, y, and d are integers and d is odd are both x and y divisible by d?
(1)x+y is divisible by d.
(2)x-y is divisible by d.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。
因为x-y,x+y都能divided by d
(x+y)+(x-y)=2x，（x+y）-（x-y）=2y 也能被d divided
d 是odd，所以x,y都能被d divided
https://gmatclub.com/forum/if-x-y-and-d-are-integers-and-d-is-odd-are-both-x-and-y-divisible-128469.html
(1) -->(x/d)'+(y/d)'=0或(x/d)'+(y/d)'=d;
(2) -->(x/d)'=(y/d)';
(1)+(2)-->(x/d)'=(y/d)'=0或(x/d)'=(y/d)'=d/2。因为d是奇数，而余数必为整数，所以(x/d)'=(y/d)'=d/2为无效解-->(x/d)'=(y/d)'=0
(2) [(x-y)/d]'=0或d-->(x/d)'-(y/d)'=0-->(x/d)'=(y/d)',不能得出x, y对d的余数是0；或(x/d)'-(y/d)'=d，也不能得出x, y对d的余数是0
(1)+(2)，如果(x/d)'-(y/d)'=d，则(x/d)'=d, (y/d)'=d；如果(x/d)'-(y/d)'=0，则(x/d)'=(y/d)'=d/2，因为d是奇数，(x/d)'必定是整数，所以该解为无效解。(1)+(2)只有一种结果，x,y都可以被d整除。
考不考虑d=1也一样