Question

一个数能被200整除,但却不能被50,100,150整除,这个数是多少?

Answer 1

200有因数2,4,5,8,10,20,25,40,50,100,200

50有因数2,5,25,50

100有因数2,4,5,10,20,25,50,100

150有因数2,3,5,6,10,15,25,30,50,75,150

从中可得200独有因数8与40即为所求