An interesting question from GMAT Prep

yaoyao99

Just for fun:

For every positive even integer n, the function h(n) is defined to be the product of all the even integers from 2 to n, inclusive.  If p is the smallest prime factor of h(100) + 1, then p is

A. between 2 and 10
B. between 10 and 20
C. between 20 and 30
D. between 30 and 40
E. greater than 40

I'll post the answer tomorrow.

lovetiky

选E吧~~

似乎大于50

[此贴子已经被作者于2006-6-4 10:53:50编辑过]

hitlzc

哈哈，yaoyao这个题讨论过多次了。

yaoyao99

*faint*  I couldn't find it myself and it took me quite awhile to figure it out...

lovetiky

lz到底答案是什么啊？

yaoyao99

It's E but 似乎 isn't good enough, =)  See if you can prove it.  I'll post the answer later today.

neversame

h(100)的prime factor从2，3。。到47。

所以h(100)+1必然不能被2,3,....47之中任意一个prime整除

所以h(100)+1的smallest prime factor必然大于47

So E