求GWD几道题目

531769079

Q5:
If b, c, and d are constants and x2 + bx + c = (x + d)2 for all values of x, what is the value of c?
(1)      d = 3
(2)      b = 6
    
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.

此题为什么选D

第二题;Q28:
Last Sunday a certain store sold copies of Newspaper A for $1.00 each and copies of Newspaper B for $1.25 each, and the store sold no other newspapers that day.  If r percent of the store’s revenues from newspaper sales was from Newspaper A and if p percent of the newspapers that the store sold were copies of newspaper B, which of the following expresses r in terms of p?

A.    100p / (125 – p)
B.    150p / (250 – p)
C.    300p / (375 – p)
D.    400p / (500 – p)
E.    500p / (625 – p)

求解题思路  谢谢哈

还有是不是GWD相对于考试比较简单啊

tangyunjie

解第一题，很简单，代入，马上发现D=3的时候C=9 B=6； 同时，当B=6的时候，D只能等于3，从而推算出，C=9.两个都可以，所以答案是D。
解第二题，如果硬是要算，那么就霸王硬上弓，比较麻烦我也弄了不少时间，设总共是X份，然后X的百分之（1-p)乘以1刀等于百分之R乘以百分之1-P乘以1刀架上百分之P乘以1.25刀（这个是总收入）从而推算出R等于P的算式。答案还是D
如果是想省时间，那么就相当简单，代入法。A报纸卖出80份，收入80刀，B报纸卖出80份，收入100刀，R=400/9，P等于50.带入5个算式，只有D能成立，把解求出，正常中国人的运算速度，只需要32秒。

531769079

那个报纸的数量为什么都相等啊