My math textbook has this problem that I'm having a lot trouble with:
All the markers in a desk drawer are black, red, or purple. All but two are black, all but two are red, and all but two are purple. How many markers are in the drawer?
I have no idea how to figure this out or what the answer is. If anyone has any ideas, please let me know and why (I really want to understand your train of thought, so stating why would be very helpful).