The riddles in Mutamin's challenge are not really difficult because you have only few possible answers (ok, don't count the riddle about the mage's daughters). But I have been thinking about one thing: is there any possibility to solve the riddle with the trinkets and girls without having a multiple choice? It reminds me of the riddle in BG2. I think it could be solved with pure math or if you didn't want to do math, the right answer could be found with little thinking.