Good but from a UK point of view in particular fuller explanations would be a good idea. And not just for Brits. For instance I knew Monty Hall because I have heard of the conundrum named after his ( US ?) game show but I doubt he is a household name even over there. Best of luck with compiling and pleasing everyone !

Very tough.

Thanks for the feedback, toast. I'll keep that in mind for future puzzles.

Too hard.