涛涛版GWD25－20、27、29、32题

sunnyever

做了涛涛的GWD的第25套，错了N多！！ 在讨论帖里也没找到很多大家的相关讨论，难道大家都没问题么？还是我太笨了？

问题如下：

 

 Q20.

Based on this year’s costs, an orcharde grower budgets P dollars for planting N new trees next year. If the average cost of planting each tree were to increase 25 percent from this year’s cost ,then the greatest number of trees that the orchard grower could plant next year using P dollars would be.

A.      20% less than N

B.      25%less than N

C.      equal to N

D.     20%greater than N

E.      25% greater than N

 

没明白题什么意思。。

 

 

Q27.

If M is a positive integer, then M^3 has how many digits?

(1) M has 3 digits.

(2) M^2 has 5 digits

_______________________________________________________________-

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

Q29.

if X>1 and Y>1, is X<Y?

(1) X^2/(XY+X)<1  

(2) XY/Y^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

我选B

Q32.

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.

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

我选D

[此贴子已经被作者于2007-3-21 16:51:55编辑过]

sammy生米

Q20. 设每棵树的成本为A，则P=N1A1=N2A2，如果A2要提高25%，即A2等于1.25 A1，
N2= N1A1/A2= N1 A1/1.25 A1= 0.8N1，即20% less than N1

sammy生米

以下是引用sunnyever在2007-3-21 16:51:00的发言：
Q27. If M is a positive integer, then M^3 has how many digits?

(1) M has 3 digits.

(2) M^2 has 5 digits

M=100，300时，(1)(2)都不充分

[此贴子已经被作者于2007-3-21 22:17:38编辑过]

sammy生米

以下是引用sunnyever在2007-3-21 16:51:00的发言：

Q29.

if X>1 and Y>1, is X<Y?

(1) X^2/(XY+X)<1  

(2) XY/Y^2-Y<1

E Statements (1) and (2) TOGETHER are NOT sufficient

我选B

if X>1 and Y>1, is X<Y?

(1) X^2/(XY+X)<1  

(2) XY/Y^2-Y<1

E Statements (1) and (2) TOGETHER are NOT sufficient

我选B

it's XY/(Y^2-Y), not (XY/Y^2)-Y

sammy生米

Q32. D 同意

sunnyever

以下是引用sammy生米在2007-3-21 22:23:00的发言：

it's XY/(Y^2-Y), not (XY/Y^2)-Y

先谢谢sammy生米

 

这道题我还有疑问： XY/(Y^2-Y)的分母可以变成Y(Y-1)，与分子的Y约分，得到X/(Y-1)。这样X<Y-1，是不是可以证明X<Y呢？

sammy生米

以下是引用sunnyever在2007-3-23 2:30:00的发言：

这道题我还有疑问： XY/(Y^2-Y)的分母可以变成Y(Y-1)，与分子的Y约分，得到X/(Y-1)。这样X<Y-1，是不是可以证明X<Y呢？

看错了，条件2应该是 (XY/Y^2)-Y < 1

sunnyever

我看成XY/(Y^2-Y)了。。。汗。。。

colorful_na

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colorful_na

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