I will be checking these puzzles to make sure I got them correctly.

One: How many white and black queens can you fit on a chess board without them attacking each other. I think the answer is 9 and 10. Can you find the solution with that number?

Two: You have 13 coins if I remember correctly, and one is counterfeit and weighs less than or more than the others. The other 12 weigh the same. You get to make three weightings on a scale; can you identify the coin no matter what?

One: How many white and black queens can you fit on a chess board without them attacking each other. I think the answer is 9 and 10. Can you find the solution with that number?

Two: You have 13 coins if I remember correctly, and one is counterfeit and weighs less than or more than the others. The other 12 weigh the same. You get to make three weightings on a scale; can you identify the coin no matter what?