If x and z are integers, is at least one of them even?
(1)x + z is odd.
(2)x - z is odd.
我选择的是E,答案给的D.
我的思路是因为没有给定X和Z都要是positive的,所以特殊值,当X=3,Z=-2的时候, 满足条件1,2, 但是没有at least one of them is even; 当X,Z都大于0的时候,满足条件1,2,这个时候at least one of them is even.所以不能确定,所以选的E.
In the decimal representation of x, where 0 < x < 1, is the tenths digit if x nonzero?
