Riddle: A forest exists somewhere on Earth. This forest has no life except for trees. After a storm, a tree was hit by lightning and falls.
What sound would it make?
Answer: None. Sound does not exist if it is unheard.
Riddle: A large truck is crossing a bridge 1 mile long. The bridge can only hold 14000 lbs, which is the exact weight of the truck. The truck makes it half way across the bridge and stops. A bird lands on the truck. Does the bridge collapse? Give a reason.
Answer: No it does not collapse. Because it has driven a half mile - you would subtract the gas used from the total weight of the truck
Riddle: A man while looking at a photograph said, "Brothers and sisters have I none. That man's father is my father's son." Who was the person in the photograph?
Riddle: Suppose you want to send in the mail a valuable object to a friend. You have a box which is big enough to hold the object. The box has a locking ring which is large enough to have a lock attached and you have several locks with keys. However, your friend does not have the key to any lock that you have. You cannot send the key in an unlocked box since it may be stolen or copied. How do you send the valuable object, locked, to your friend - so it may be opened by your friend?
Answer: Send the box with a lock attached and locked. Your friend attaches his or her own lock and sends the box back to you. You remove your lock and send it back to your friend. Your friend may then remove the lock she or he put on and open the box.