Mathematical Induction :P

今天上课时，lecturer 给了我们一道难题：
Prove by induction that all sheep are the same colour.
很难吧?? 呵呵...
这时大家都精神起来，开始议论纷纷...
好吧，公布答案...
proof:
Let n be the number of sheep.
When n=1, the statement is true.
Assume that when n=k the statement is true that is ksheep are the same colour.

When n=k+1,
(k+1)sheep=k sheep+ sheep
therefore, (k+1) sheep are the same colour.

Hence,by the principle of mathematical induction, we can prove that all sheep are the same colour.
呵呵... 蛮有道理的吧??

今天在我apartment楼下遇到文欣，对就是商三A的吴文欣。很巧吧??
跟她聊了一下，她说，她哥哥读精算第一年时大约有四百人。
第二年只剩下大约一百人，到honourdegree毕业整四十人...
天啊....谁来救救我...
没眼睛看了... =.=