Ideaal! is looking for puzzles!

W.S.G. Abacus, the UT mathematical study association, is making a puzzle booklet for all math and computer science students of the Netherlands, and would like your help!

For this, they need some puzzles to be put in this puzzle booklet, and would like to receive your help in making some of these puzzles. If you are willing to help out with this project, feel free to send your puzzles to before the 5th of May!