国际顶尖MBA申请交流平台--TOPWAY MBA

标题: 求一道prep 数学题解答 [打印本页]

作者: summergal 时间: 2013-7-6 17:07 标题: 求一道prep 数学题解答

For every positive even integer n, the function h(n) is defined to be the product of all the even integers from 2 ton, 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

答案选E ，想不通，请大牛们帮忙解释一下

作者: songxueer 时间: 2013-7-7 08:02

h(100)+1=2*4*8*......*100+1=2^a*3^b*5^c*....*47+1
h(100)的质因数包含2到47之内的所有质数，所以h(100)+1不可能有低于47的质因数。

作者: shenchen 时间: 2014-6-26 17:22

赞 32个

作者: oeasy 时间: 2014-7-3 16:56

欢迎光临国际顶尖MBA申请交流平台--TOPWAY MBA (http://forum.topway.org/)