Squigly Squigly's Brain Teasers

Question:

Which of these numbers are prime numbers: 7, 8, 9, 10, 11, 12, 13, 14?

Answer:

7, 11, 13.

Try another Brain Teaser:

You walk across a bridge and you see a boat full of people yet there isn't a single person on board. How is that possible?