IMC 2023 · Problem 6
Statement
Ivan writes the matrix on the board. Then he performs the following operation on the matrix several times:
- he chooses a row or a column of the matrix, and
- he multiplies or divides the chosen row or column entry-wise by the other row or column, respectively.
Can Ivan end up with the matrix after finitely many steps?
Official solution
Proposed by Alex Avdiushenko, Neapolis University Paphos, Cyprus.