2
$\begingroup$

This is a question from the 1998 math olympiad I found 2 solutions in the following places: book1 pg.32 book2 pg.163 however, I was having trouble understanding them. Any help would be appreciated

There is a 98 × 98 chessboard, colored in the usual way. One can select any rectangle with sides on the lines of the chessboard and as a result, the colors in the selected rectangle switch (black becomes white and white becomes black). What is the minimum number of changes needed to make the chessboard all one color?

$\endgroup$

closed as off-topic by Rory Daulton, Adrian Keister, Jens, Holo, user91500 Jan 15 at 6:40

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question is missing context or other details: Please provide additional context, which ideally explains why the question is relevant to you and our community. Some forms of context include: background and motivation, relevant definitions, source, possible strategies, your current progress, why the question is interesting or important, etc." – Rory Daulton, Adrian Keister, Jens, user91500
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    $\begingroup$ Welcome to MathSE! You are more likely to get a good answer to your question if you follow a few guidelines. In particular, what have you tried so far, and just where are you stuck? This is not a homework-answering site: many of us want to see that you have put significant work into the problem. $\endgroup$ – Rory Daulton Jan 15 at 1:50
  • 1
    $\begingroup$ Yes, even if that is just providing further details as to precisely what part of the textbook explanation you don't follow. I would assume Olympiad problems are not your homework, but a task you are working on for enrichment. $\endgroup$ – bounceback Jan 15 at 5:06