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标题: 求助数学GWD 二战在即 [打印本页]

作者: xiahuistacy    时间: 2010-1-5 14:52
标题: 求助数学GWD 二战在即
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Q32:

In the decimal representation of x, where 0 < x < 1, is the tenths digit of x
nonzero?
(1)     16x is an integer.

(2)     8x is an integer.

                 

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.

Answer: B  这个题目我选的是D 其实是瞎选的 因为我不知道怎么下手做 请大家指点 谢谢
作者: mydloveal    时间: 2010-1-5 15:01
X是个小数,问X的十分位是不是0 。
条件1:就是说X是(1~15)/16,如果是1/16那么十分位就是0了,15/16就不是0,所以不确定,无法解答问题
条件2:就是说X是(1~8)/16,从1/8到7/8,十分位都不是0

选B




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