作者gippholugan (ambition)
看板GRE_Verbal
标题Re: [计量] PP3的题目
时间Wed Oct 24 20:09:29 2007
※ 引述《volvox (╮(﹀_﹀")╭)》之铭言：
: The "reflection" of a positive integer is obtained by reversing its digits.
: For example, 321 is the reflection of 123. The difference between a
: five-digit integer and its reflection must be divisible by which of the
: following?
: (A) 2 (B) 4 (C) 5 (D) 6 (E) 9
: 我算出来结果是答案A和答案E都可以
: 因为差值是偶数 所以我就选了A 结果答案是E
: 我的算法是54321-12345=41976
: 请问各位版友 我是哪里算错了呢?
: 谢谢
五位数abcde
10000a+1000b+100c+10d+e -10000e-1000d-100c-10b-a
=9999a+990b-990d-9999e = 9(1111a+110b-110d-1111e)
所以9一定对
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 220.135.238.39
1F：推 volvox:喔 我了解了 原来题目并没要求要连续数列 210.203.59.224 10/24 21:46
2F：→ volvox:谢啦! 210.203.59.224 10/24 21:47