"Heard on the Street" by Timothy Falcon Crack is a collection of brainteasers that were supposedly put to interview candidates for Wall Street jobs. The book has many more questions like the ones you asked - most of them can be solved without any heavy mathematical machinery, but they all require a little ingenuity.

Sadly, the book has become famous enough that recent graduates hoping to get banking jobs often memorise all the problems, rendering the whole process useless.