[y] denotes the greatest integer less than or equal to y. Is d < 1 ?
(1) d = y - [y]
(2) [d] = 0
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.
题目分析:
[y]表示小于或等于y的最大整数。
(1) [y]是不超过y的最大整数,所以y-[y]的最小值为0,即y为整数的情况。y-[y]最大值必然小于1。
(2) 满足[d]=0,即不超过d的最大整数为0,所以d的取值范围为0<d<1,如果2>d≥1,则[d]=1。所以[d]=0满足要求。
因此,本题答案为(D),任何一个条件说明均能解题。
y-[y]最大值必然小于1。
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