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标题: 真是不会做这种类型的DS题啊!!! [打印本页]

作者: wjk    时间: 2011-4-4 22:03
标题: 真是不会做这种类型的DS题啊!!!
If p and n are positive integers and p > n, what is the remainder when p^2 – n^2is divided by 15 ?

(1) The remainder when p + n is divided by 5 is 1.

(2) The remainder when p - n is divided by 3 is 1.
答案:E
这类题目看似挺复杂的,有什么专门解这类题的思路吗?谢谢

作者: carbonzju    时间: 2011-4-4 22:07
(p+n)(p-n)
作者: carbonzju    时间: 2011-4-4 22:12
可以带两个数试下, 不一致就选e了




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