[原创]3.29 jj

zhliang2000

AA:

Management of recreation center saw the increase in the number of membership after the opening of new swimming pool. They conclude that more new facilities such as golf, multipurpose game center will boost the revenue further

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AI:

Which one should organization value more,     advices from outside expert or those from inside experienced employees.

    

Math:

A lot of jj in cd has appeared in the test. The only with some difficulties and without seen before is:

DS: One guy opened an account in two different banks with same amount of deposit. Bank X provides an annual interests rate x, compound quarterly. Bank Y provides one with annual interests y, compound semiannually. Is x > y?

1. After one year, both deposit receives same amount of interests
   
2. the combined interests received > 120

    

(1+x/4)^4 = (1+y/2)^2

(1+(8x+x^2)/16)^2 = (1+y/2)^2

8x+x^2 = 8y

8(y-x)=x^2>=0


Combine with 2, the choice is C

donna

谢谢分享！

lotery

thanks        


but i think the jj's ans is (A)


x^2+8x=8y     那     (x^2)/8 + x = y    
也就是x<y 囉


尚请nn指点

pippi

谢谢分享！


好好休息一下先

terp

thanks.

橙子

谢谢分享!

pinpin

I think answer is "A"

zhliang2000

HI, everyone.


I still think to answer is C. Because 8(y-x)=x^2 does not necessarily mean y-x > 0, it could mean x=y. So combined with 2, which means x > 0, then we can reach the conclusion y>x.


I think this is the trick of the question

kevinwj

以下是引用zhliang2000在2004-4-2 7:52:00的发言：
HI, everyone.



I still think to answer is C. Because 8(y-x)=x^2 does not necessarily mean y-x > 0, it could mean x=y. So combined with 2, which means x > 0, then we can reach the conclusion y>x.


I think this is the trick of the question

    


thanks for your JJ


我想根据题意应该理解x,y都不是0，所以应该选A，否则如果需要通过2来判断x,y都不是0，那ETS也真脑子有毛病了，大家说呢