Before Mount Everest was discovered, what was the highest mountain in the world?

Solve this riddle by finding the odd one out from the rest.

Replace the question mark with the correct number below.

John was visiting his friend Jacob. He found out that his friend's wife had just killed a burglar in self-defense.
John asks Jacob about what happened and he told that "His wife was watching television when suddenly the bell rang. She thought that it is her husband Jacob but she found the burglar who attacked her instantly and she got so frightened that she killed the burglar immediately with the knife.
John asked the police to arrest his friend's wife. Why?

Why is a river so rich ?

What number divided by 4 is the same as that number minus 4?

Two friends Smith and Andrew were talking about the bravery of their families. Smith told great stories about his courageous grandfather who fought for Britain in "World War I". Andrew told that his grandfather was so brave that in 1919 just after the war he was honoured with a bravery medal with the words "For our Courageous Soldiers In World War I" embedded into it. Smith knows that his friend is lying. How?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What does the below image rebus riddle means ?