This is quite funny problem I found, also known as the Wason Selection Task. You are shown these four cards, which one one side have a number and have a colored back:

You want to verify the following theorem: "If the number on a card is even, then the back is blue."
What cards do you (minimally) need to turn over to verify the theorem?

This is a very interesting problem indeed!

I gathered the right answer (checked wikipedia if I was correct), but I got there by "proof by exhaustion" do you know of any other/more elegant way to arrive at the correct solution?

Here's what I came up with (spoilers):

We don't need to check the first card because it doesn't have an even number on it, and we don't need to check the last card because, since it's blue, if it has an odd number we don't care. We do need to check the second and 3rd cards because either one of them could disprove the theorem.

Oh! I just got it. Nice puzzle! I'll have to share this!

I throw this on the board as a warmup in an intro-level math class, didn't know it had a name though, so that's pretty neat. It's not so much a puzzle, though, it's more just "do you understand the meaning of the word IF?"