Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

John buys rice at Rs.60/kg from Britain and then sells them at Rs.5/kg in India. As a result of this, he becomes a millionaire. How come?

Which is faster, Heat or Cold ? Explain.

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?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

You Throw The Outside, Cook The Inside
Eat The Outside, Throw The Inside.

What Is It?

I always drive my customer away.

Who am I?