[求助] 数学题

Henrik

Is the integer n odd?

1) n is divisible by 3

2) 2n is divisible by twice as many positive integers as n.

B(第二个条件要怎么理解呢? )

谢谢

willwang0110

2n的因数个数是n的因数个数的两倍~~

企企

2n是n的因数的两倍，说明n里面没有2这个因子，所以n肯定是odd...

Henrik

Hey, 谢谢楼上,明白了.