Math Riddles

Question: Ants on a stick may only move left or right. If they bump into each other they bounce off of each other and immediately move in the opposite direction maintaining speed the entire time. The only time they change speed is when they fall off of the edge of the stick.

If 25 ants are randomly put on a 1 meter long stick moving 1 meter per second, what is the longest amount of time it could take for them to all fall off?

Question: 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?

Question: If you have a cake, how many pieces of cake can you form with 3 straight cuts?

Question: You have two buckets: one with only white marbles and one with only black marbles. The two buckets have the same number of marbles.

How can you rearrange the marbles to maximize your chances of grabbing a white marble from each?

Question: If 4+5=24 7+2=21 9+6=63 6+7=?