HMMT 二月 2008 · GEN1 赛 · 第 2 题
HMMT February 2008 — GEN1 Round — Problem 2
题目详情
- [ 3 ] Find the smallest positive integer n such that 107 n has the same last two digits as n .
解析
- [ 3 ] Find the smallest positive integer n such that 107 n has the same last two digits as n . Answer: 50 The two numbers have the same last two digits if and only if 100 divides their difference 106 n , which happens if and only if 50 divides n .