[求助]TTGWD24难道我眼花了?

raikey

9

The operation* represents either addition, subtraction, or multiplication of integers, what is the value of 1*0?

(1)   0*2=2 

(2)    2*0=2

 

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

D怎么不对? 加、减或乘嘛......

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12

During a 10-week summer vacation, was the average (arithmetic mean) number of books that Carolyn read per week greater than the average number of books that Jacob read per week?

(1)   Twice the average number of books that Carolyn read per week was greater than 5 less than twice the average number of books that Jacob read per week.

(2)   During the last 5 weeks of the vacation, Carolyn read a total of 3 books more than Jacob.

 

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

居然是A,不明白.

根据题意: 2C>2J-5也就是J-C<2.5 , 如果J比C小,该不等式永远成立,不是吗?所以E有何不对?

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28

If k=-1, which of the following is (are) true?

1. k^k=k  2. | k| =-k.   3.k^0=-k

 A. 1 only   B. 1 and 2 only   C. 1 and 3 only  

 D. 2 and 3 only    E.  1. 2. and 3.

受打击了,答案竟然选E......

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joy110211

以下是引用raikey在2007-6-6 0:13:00的发言：

9

The operation* represents either addition, subtraction, or multiplication of integers, what is the value of 1*0?

(1)   0*2=2 

(2)    2*0=2

D怎么不对? 加、减或乘嘛......
        

        

是A吧?
        

第2個條件裡, *可以是加或是減
        

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28

If k=-1, which of the following is (are) true?

1. k^k=k  2. | k| =-k.   3.k^0=-k

 A. 1 only   B. 1 and 2 only   C. 1 and 3 only  

 D. 2 and 3 only    E.  1. 2. and 3.

受打击了,答案竟然选E......

是E沒錯.

1. K^K=K ==> -1^-1=1/-1=-1=K (1/-1還是等於-1)

2. |K|=-K ==> |-1|=-(-1)=1 (abs -1 和-(-1)都是1)

3. K^0=-K ==> -1^0=1=-(-1)=-K (任何數raise to the power of 0都會等於1)

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If k=-1, which of the following is (are) true?

1. k^k=k  2. | k| =-k.   3.k^0=-k

 A. 1 only   B. 1 and 2 only   C. 1 and 3 only  

 D. 2 and 3 only    E.  1. 2. and 3.

受打击了,答案竟然选E......

是E沒錯.

1. K^K=K ==> -1^-1=1/-1=-1=K (1/-1還是等於-1)

2. |K|=-K ==> |-1|=-(-1)=1 (abs -1 和-(-1)都是1)

3. K^0=-K ==> -1^0=1=-(-1)=-K (任何數raise to the power of 0都會等於1)

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中間那題, 我也以為是E

raikey

9: 无论是加还是减, 1*0总归等于1啊!

28: 是我糊涂了,把 k^k看成是k*k了, 看来该早点睡觉了.