作者william1001 (康)
看板GMAT
标题[计量] PP1-Q7
时间Wed Jul 23 11:29:55 2008
7.
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
这题解法由(2*4*6*8...*100)+1=2^50*50!+1 解起
我想问的是为什麽(2*4*6*8...*100)+1 会等於 2^50*50!+1 ?
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1F：推 tgbh:(2*4*6*8...*100)+1 = 2[1*2*3*4....*50]+1 07/23 11:51
2F：→ william1001:所以是 2*50!+1而不是 2^50*50!+1 ? 07/23 12:35
3F：推 DanceDan:2要提五十次出来~所以是2^50 07/23 20:19
4F：→ DanceDan:请问接下来怎麽解啊? 07/23 20:19