If x and y are positive integers, what is the remainder when 10x + y is divided by 3 ?

(1) x = 5

(2) y = 2

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.

##### 考题讲解

（1）  如果x=5，则~$10^x+y=10000+y$~，此时10000+y不止1个，例如y=1，10000+y=10001，其除3的余数为2，如果y=2时，10000+y=10002，其除3的余数为0。所以。条件1不能确定~$10^x+y$~的余数。

（2）~$10^x$~    除以3的余数必为1，若y=2，则~$10^x+y$~的余数必为0。也就是说y=2时，~$10^x+y$~必能被3整除。