About Finding optimal taxation policy- constrained optimization, wolfies, Sascha, corey979, Bob Hanlon, Feyre I think you have been unkind to close the question of Nofar Duani. She is a beginner on this site and doesn't know the rules but her question can be answered without a Wolfram expert. So I do not know if I break the rules but I give a cross answer to her question. Unfortunately, I have no mean to signal this the her attention.