Food for Thought

Yeah, I know. I've been a bad blogger. Well, I'll try and turn that around by blogging fairly regularly again, starting this weekend. In the meantime, mull over this one:

If McDonalds sells its new Chicken Selects in boxes of 6, 9 and 20, what's the largest number of new Chicken Selects that you CANNOT exactly purchase?

Was that unclear?

Well, here's an example: I CAN purchase 15 Chicken Selects, (one box of 6 and one box of 9). I CANNOT buy exactly 16. I CANNOT buy 17. I CAN buy 18. Get it? Great!