What always comes into a house through the keyhole?

You are confined in a room and given two metal rods. Out of these two rods, one is magnet and the other is the iron rod. They look starkly similar. You don't have any other metal object in the room.

How will you decide which one of those is magnet?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

How is a fly different from a mosquito?

Using eight eights and addition only, can you make 1000?

What kind of band never plays music?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

What you cannot hold but it is yours?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?