求助2道GWD DS题，非常感谢

zccwen

1.

This year Henry will save a certain amount of his income, and he will spend the rest.  Next year Henry will have no income, b.  In terms of r, what fraction of his income should Henry save this year so that next year the amount he was available to spend will be equal to half the amount that he spends this year?

 A. 1/(r+2)

 A. 1/(r+2)

 B. 1/(2R+2)

 B. 1/(2R+2)

 C. 1/(3r+2)

 C. 1/(3r+2)

D. 1/(r+3)

D. 1/(r+3)

E. 1/(2r+3)

E. 1/(2r+3)

为啥选E，谢谢

为啥选E，谢谢

2.

What is the sum of a certain pair of consecutive odd integers?

(1)     At least one of the integers is negative.

(2)     At least one of the integers is positive.

                  

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.

如何理解 a certain pair of consecutive odd integers 这个概念？  3，－3 算是一对连续的奇整数吗？

What is the sum of a certain pair of consecutive odd integers?

(1)     At least one of the integers is negative.

(2)     At least one of the integers is positive.

                  

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.

如何理解 a certain pair of consecutive odd integers 这个概念？  3，－3 算是一对连续的奇整数吗？

2.

What is the sum of a certain pair of consecutive odd integers?

(1)     At least one of the integers is negative.

(2)     At least one of the integers is positive.

                  

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.

如何理解 a certain pair of consecutive odd integers 这个概念？  3，－3 算是一对连续的奇整数吗？

What is the sum of a certain pair of consecutive odd integers?

(1)     At least one of the integers is negative.

(2)     At least one of the integers is positive.

                  

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.

如何理解 a certain pair of consecutive odd integers 这个概念？  3，－3 算是一对连续的奇整数吗？

What is the sum of a certain pair of consecutive odd integers?

(1)     At least one of the integers is negative.

(2)     At least one of the integers is positive.

                  

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.

如何理解 a certain pair of consecutive odd integers 这个概念？  3，－3 算是一对连续的奇整数吗？

floridadream

第一题你贴的好像有毛病

第二题应该是C

连续的奇整数只有在异号的情况下 和才能确定  也只有-1和1满足条件

3和-3中间有1和-1，所以不算连续的奇整数

hanxiao513

题目应该是： 

This year Henry will save a certain amount of his income, and he will spend the rest. Next year Henry will have no income, but for each dollar that he saves this year, he will have 1 + r dollars available to spend. In terms of r, what fraction of his income should Henry save this year so that next year the amount he was available to spend will be equal to half the amount that he spends this year?

假设：总收入x，存了y,那么花了(x-y)

第二年他能得到(1+r)y

令(1+r)y=(1/2)(x-y)

将两边同时除以y，解得(x/y)=2r+3

则(y/x)=1/(2r+3)

[此贴子已经被作者于2009-7-13 12:48:17编辑过]

zccwen

Many thanks, really appreciate ur help.