Hi Dan, Yes, they, like all nonprofits, want donations. But they aren’t pushy. I find them a worthy cause. There were “chat” requests on the Zoom meeting suggesting they put the puzzles online. At least one was from Winkler’s books. He is working on another book, that will include (some? all?) of these MoMath ones. Many of the puzzles are from other sources. Voted most favorite puzzle (24% of votes) was “Factorials and Squares”: from the product 1! * 2! * 3! * … * 100!, remove one “term” K!, to make the result a perfect square. Attributed to Jeremy Kun. I just now posted computer results on the generalized 1! … N!, to https://math.stackexchange.com/questions/854808/product-of-factorials-divide... <https://math.stackexchange.com/questions/854808/product-of-factorials-divided-by-factorial-to-produce-perfect-square> Voted second favorite (15%) was “The King’s Salary”: "Democracy has come to the little kingdom of Zirconia, in which the king and the other 65 citizens each have a salary of one zircon. The king cannot vote, but he has the power to suggest changes — in particular, redistribution of salaries. Each person's salary must be a whole number of zircons, and the salaries must sum to 66. Each suggestion is voted on and carried if there are more votes for than against. Each voter can be counted on to vote "yes" if his salary is to be increased, "no" if decreased, and otherwise not to bother voting. The king is both selfish and clever. What is the maximum salary he can obtain for himself, and how many referenda does he need to get it?" Voted third (13%) was “Oskar and the Ostrich Eggs”, a quality assurance problem dropping eggs from varying floors of the Empire State Building (102 floors) to determine max height where they break; I think from the Winkler book. The QA guy has 2 eggs; how many drops must he make? Voted fourth (11%) was “Same Sum Subsets”: "Amy asks Brad to pick ten different numbers between 1 and 100, and to write them down secretly on a piece of paper. She now tells him she's willing to bet $100 to $1 that his numbers contain two nonempty disjoint subsets with the same sum! Is she nuts?" — Mike

On Aug 26, 2020, at 9:59 AM, Dan Asimov <dasimov@earthlink.net> wrote:

There's no reason anyone should have to "sign up" when MoMath could easily just post the problems on their website. I suspect they just want a bunch of people they can hit up for money.

Peter Winkler has written at least two books of mathy puzzles, which I own. Can it be that these puzzles are from those?

Could you (Mike) post a few of the best ones to math-fun?

—Dan

----- I think MoMath’s weekly puzzle series hasn’t been mentioned on math-fun. In case you want a nice weekly puzzle, consider subscribing (it’s free). They range from numerical, to logical, to somewhat geometric. None require any math beyond algebra, and they each involve some kind of “aha!” insight, explained in the solution sent 6 days later. -----

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