Kittens Problem
This problem comes from the Mathematical Assessment Project. More details can be found http://map.mathshell.org/lessons.php?unit=9100&collection=8&redir=1. It's a good problem and very topical as more than one town is dealing with feral cat populations. I heard a story on NPR just the week of August 22 which I will try to find and link to here.
Kittens Problem.pdf
Kittens How did you work.pdf
Kittens Sample Solutions.pdf