Number Properties Puzzle – Challenge 11
This is another great math challenge for those who love critical thinking challenges. This puzzle doesn’t require advanced mathematical knowledge, just logical reasoning. Let’s see how smart you are!
Number Properties Puzzle – Challenge 9
Number Properties Puzzle – Challenge 9 asks how many positive integers below 10,000 have digits summing to 5. Counting them one by one is hopeless; the puzzle is really a stars-and-bars problem, distributing 5 units across four digit positions.
