Q13:

What is the remainder when the positive integer n is divided by 3?

(1)     The remainder when n is divided by 2 is 1.

(2)     The remainder when n + 1 is divided by 3 is 2.

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可 为什么不能选D，我觉得第一个条件可以满足吧～～～请大牛们赐教～～

恩,此题我也觉得选B.

N+1=3M+2

所以,N=3M+1

所以,N除以3余1.

 哦，谢谢，我明白了， 主要是昨天做题太晕了， 然后没有反应过来，其实我就是不知道为什么第一个条件为什么不能成立，今天 突然想开了.

举反例就可以，5，7除2都余1，但5除3余2，7除3余1，因此不能确定