MathCastle
Proof WritingSuperchallengeInduction

Induction · Superchallenge problem

Planes in general position: when the (k+1)(k + 1)-th plane is added, the kk old planes cut it along kk lines in general position, which divide it into R(k)=1+k(k+1)2R(k) = 1 + \dfrac{k(k + 1)}{2} pieces, and each piece splits a region of space in two. How many regions do 1010 planes make?