这题脑子转不过来了。。。
If n and t are positive integers, what is the greatest prime factors of the product nt?
1)The greatest common factor of n and t is 5
2) The least common multiple of n and t is 105
whyB?
条件1肯定不行,因为不common的factors可能大于5,比如n有一个factor是7,那么nt肯定也有factor为7;
条件2行,因为105可以分解为5、3、7这三个prime factor,而n、t就是这三个数的组合,比如15、7;5、21之类的,但最大的prime factors 肯定是7了
欢迎光临 国际顶尖MBA申请交流平台--TOPWAY MBA (http://forum.topway.org/) | Powered by Discuz! 7.2 |