一道GMAT PREP 数学题

ritafu

 实在不知道这道题怎么解，请指教！

For every positive even integers, the function F(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

答案适是ｅ，谢谢！！

G0606

这题原来讨论过，F（100）的最大质因子47，47以下的所有质因子都是F（100）的质因子，F（100）和F（100）+1没有共同的质因子，F（100）+1的最小质因子只能大于47