请求关于数学的审题明细

niuniupig

这个是OG上的说明，除了what is 这种问法，还有那种问法需要算出DS题干里所需的精确值，而不是大概？哪些问法只要大概就行了，当然最好有例题～？谢谢亲们～
For example, if the question asks, “What is the value of y ?” for an answer statement to be
sufficient, you must be able to find one and only one value for y. Being able to determine
minimum or maximum values for an answer (e.g., y = x + 2) is not sufficient, because such
answers constitute a range of values rather than the specific value of y.

niuniupig

ei～没人啊没人～

niuniupig

不给力啊~ 都没这样的问题么？

ZQL

那这道题不是跟OG的解释相悖了吗？郁闷
If x and y are positive integers and y = 根号(9-x), what is the value of y?
(1)  x < 8
(2) y > 1
    
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.
答案选D，GWD9-5，还是答案错了？

cynthia1991

那这道题不是跟OG的解释相悖了吗？郁闷
If x and y are positive integers and y = 根号(9-x), what is the value of y?
(1)  x < 8
(2) y >1

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.
答案选D，GWD9-5，还是答案错了？

-- by 会员 ZQL (2011/11/4 20:19:42)

答案没错呀。首先根据9-X >0且x是正整数可以得到0<X <9.然后看条件一，得到0<X <8，故只有当x=5的时候才有一个y是正整数，为4，sufficient。
条件二可得，根号(9-x）>1，故得到0<X <8，同样只能得到y=4，所以sufficient。
选D