Unfortunately I feel that the answer to this question is actually a bit more complex than just just asking about concentrations and how they relate to pH.
Yes, you can sit down with a pencil and paper and show if the concentrations of the solutions required to produce these pH values are reasonable. But at the end of the day, if you stick a pH meter in 2M sodium hydroxide, it's going to spit out a value in the 13 range. Then you're sitting there with your pencil and paper thinking about how you calculated something above 14.
This is mostly due to something called activity interference, which I'm sure you don't learn about in your high school chemistry class. It's something you learn in analytical chemistry.
Basically what this all means is that once you start reaching concentrations above a certain point you begin to see non-ideal behavior.
Granted, I've never sat there with a pH meter and tried to push the pH of a solution past 14, so I don't actually know the answer to your question.
If you can, I suggest not sitting down with a pen and paper, but actually trying to make solutions that will go out of the range of a pH meter. Ask your teacher! You never know what they might let you do.