Why Aeroplane windows are round?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

A shopkeeper allows people to buy a cold drink bottle in exchange for five empty bottles. A guy had a party at home and spent 77 cold drink bottles at the party. Now he has 77 empty bottles with him.

How many bottles do you think he can buy in exchange for those 77 empty bottles?

There is a family that live in a round house. The two parents go out for a movie and leave a babysitter to watch their son. They come back and the kid was not there. Some one kidnapped him. The maid said she was cleaning in a corner. The cook said he was making pizza. The babysitter said she was getting a board game. Who kidnapped him.

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

What does this mathematical rebus means ?

What's a single-digit number with no value?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?