Thanks for the backup, FeeFee and Eclipse! Sometimes my brain desn't work that fast!
Sometimes I am guilty of what I accuse my students of when they try brainteasers. I always teel them, "You're thinking too hard!" The answers usually seem obvious and then you feel crazy when you get it wrong. It's cool. I like to learn!! I just bought a book of brainteasers and stuff for my students. They really work the brain.