Who discovered South Africa

被災地でも新学期が始まったとニュースで聞きました。今日の話題は学校にちなむジョークを三つ取り上げます。出来の悪い学生と優秀な（？）学級の話の順に並べました。
・A math joke
Teacher, I can't solve this problem.
Any five year old should be able to solve this one.
No wonder I can't do it then, I'm nearly ten!
・test　
Teacher: I hope I didn't see you looking at Fred's test paper.
Pupil: I hope you didn't see me either!
・Who discovered South Africa
Teacher: Alex, can you please find South Africa on the map?
Alex: Here it is!
Teacher: Correct! Now class, who discovered South Africa?
Class: Alex!