You are surrounded by a 100 foot wide and 100 foot deep moat. You have a 40 foot tall ladder, matches, a gallon of water, and as much rope as you need.

How can you get across the moat?

Frogger the magic frog can jump 10 feet using his magical magic jump, but his magic loses its power by a half each time, so his next jump only goes as far as 5 feet. The next jump will take him 2.5 feet, and so on. How many jumps does it take to make it all the way across a 100 foot long pond?

How many cubic feet of earth are removed... ...to make a hole 4 feet wide by 7 feet long by 2 feet deep?

A knight comes to a castle where his love is trapped. The castle is surrounded by a square moat that is 10 feet wide (it forms a square around the castle). The knight is able to fashion two 9 foot long planks to cross the moat.

How can he do this?