The Crazy Math Problem in Madoka Magica

In this video, we take a look at this rather difficult Math question taken from the anime Madoka Magica. In the anime, the students are all of middle-school age but have to solve a notorious Math question which featured in the University of Tokyo entrance examination. In this video, I will spare you the torture and walk you through the solution instead.
More importantly, I will illustrate a few important Math techniques which are useful when it comes to solving recursion problems, as well as go through a few more general techniques: how to play around with information given in the problem and spot useful patterns.