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AIME 2003 I · 第 1 题

AIME 2003 I — Problem 1

专题
Contest Math
难度
L4
来源
AIME

题目详情

Problem

Given that

((3!)!)!3!=kn!,\frac{((3!)!)!}{3!} = k \cdot n!,

where kk and nn are positive integers and nn is as large as possible, find k+n.k + n.

解析

Solution

Note that

((3!)!)!3!=(6!)!6=720!6=720719!6=120719!.{{\left((3!)!\right)!}\over{3!}}= {{(6!)!}\over{6}}={{720!}\over6}={{720\cdot719!}\over6}=120\cdot719!. Because 120719!<720!120\cdot719!<720!, we can conclude that n<720n < 720. Thus, the maximum value of nn is 719719. The requested value of k+nk+n is therefore 120+719=839120+719=\boxed{839}.

~yofro