标题: 求教三道GWD数学题 [打印本页] 作者: Maggie草 时间: 2011-10-31 16:57 标题: 求教三道GWD数学题 1. if X>1 and Y>1, is X<Y? (1) X^2/(XY+X)<1 (2) XY/Y^2-Y<1
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient
lStatement (2) ALONE is sufficient, but statement (1) alone is not sufficient
lBOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
lEACH statement ALONE is sufficient
Statements (1) and (2) TOGETHER are NOT sufficient
这题为什么是E呢，我怎么觉得是B呀
2. Last year in a group of 30 businesses, 21 reported a net profit and 15 had investments in foreign markets. How many of the businesses did not report a net profit nor invest in foreign markets last year? (1) last year 12 of the 30 businesses reported a net profit and had invest- ments in foreign markets. (2) last year 24 of the 30 businesses reported a net profit or invested in foreign markets, or both.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient
lStatement (2) ALONE is sufficient, but statement (1) alone is not sufficient
lBOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
lEACH statement ALONE is sufficient
Statements (1) and (2) TOGETHER are NOT sufficient
这道题貌似之前也讨论过，但是我还是想要一个比较明确的答案，为什么是B，不是D呢
3. If the average (arithmetic mean) of the assessed values of x houses is $212,000 and the average of the assessed values of y other houses is $194,000, what is the average of the assessed values of the x+y houses?
(1)x+y=36 (2)x=2y
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.