MathProblem 5 Three wise men and mischievous boy problem
While three wise men are asleep under a tree a mischievous boy paints their foreheads red. Later they all wake up at the same time and all three start laughing. After several minutes suddenly one stops. Why did he stop?
Solution
这道题的关键在于这三个都是聪明的。在刚开始这些人都一起笑。试想一下,如果只有两个人被涂画了,那会是什么情况?
如果只有两个人,那么在其中一个人看来,另一个被涂画的人在笑,那么显然并不可能是剩下那个没有被涂的人,所以另一个被涂画的人笑话的必定是自己。所以这种情况下,并不需要“几分钟”,他们可以立即判断出来。而之所以突然有一个停下,是因为他意识到自己也被涂画了