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标题: 求助,有题不会,请指教 [打印本页]

作者: qiqiusa    时间: 2007-12-2 01:07
标题: 求助,有题不会,请指教

    

4. If n
is a positive integer and  n*2
n的平方)is divisible by 72, then the largest positive integer that must
divide n is


    

A. 6       
B. 12           C. 24        D.36       E. 48


    

正确答案是:B


    

能帮我解释一下吗??谢谢……

作者: atc    时间: 2007-12-2 02:05

72=6×6×2,那么N里面肯定有6和2啦,所以the largest positive integer that must divide n只能是12啦!


作者: qiqiusa    时间: 2007-12-2 11:53
小弟不才,谢谢赐教,嘿嘿……




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