MathDB
Putnam 2018 B1

Source:

December 2, 2018
PutnamPutnam 2018

Problem Statement

Let P\mathcal{P} be the set of vectors defined by P={(ab)|0a2,0b100,anda,bZ}.\mathcal{P} = \left\{\begin{pmatrix} a \\ b \end{pmatrix} \, \middle\vert \, 0 \le a \le 2, 0 \le b \le 100, \, \text{and} \, a, b \in \mathbb{Z}\right\}. Find all vP\mathbf{v} \in \mathcal{P} such that the set P{v}\mathcal{P}\setminus\{\mathbf{v}\} obtained by omitting vector v\mathbf{v} from P\mathcal{P} can be partitioned into two sets of equal size and equal sum.