[求助]求助 GWD-2-M2

jojofgasw

求助GWD2-M2

Q2:

If n is a positive integer and the product of all the integers from 1 to n, inclusive, is divisible by 990, what is the least possible value of n?

A. 8

B. 9

C. 10

D. 11

E. 12

这题选D, 990=9*10*11, 求least possible value of N, 为什么不是9 呢? NN 请帮忙, 谢谢先!!!

himba

題目已經寫的很明白了

mikejia

11 is primer number, n!/990 ,

990 has factors: 11*3^3*2*5. we have to find 11 as the factor of n!