請問GWD 數學2-9

lydia1018

Q9:
 

If n and t are positive integers, is n a factor of t?
 

(1)    n = 3^n-z
 

(2)    t = 3ⁿ
 

                  

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.
 

這一題我選C….但答案是E(後來發現有答案C的版本)…..
 

因為我的理解是:  t = 3ⁿ = 3^z(3^n-z) = 3^z n 這樣不對嗎? 

Z應該不至於是分數因為這樣n為正整數的的條件就破壞掉了
後來答案E我發現如果運用到log似乎可以理解 ((n=5 帶入1式  z=5-log5以3為底)

但是GMAT的數學會考到log嗎??我現在不知道到底答案該是C對還是E對了   @@

可以請大家提供一下意見嗎 @@?

[此贴子已经被作者于2007-11-28 16:24:42编辑过]

yanyan0621

i think c is right

shenjiahui

1算不算是FACTOR啊