Problem #PRU-115386

Problems Algebra and arithmetic Word problems Tables and tournaments Tables and tournaments (other) Set theory and logic Theory of algotithms

Problem

In the \(4 \times 4\) square, the cells in the left half are painted black, and the rest – in white. In one go, it is allowed to repaint all cells inside any rectangle in the opposite colour. How, in three goes, can one repaint the cells to get the board to look like a chessboard?