Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

What is black when you buy it, red when you use it, and gray when you throw it away?

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

What is the fastest way to double your money?

What will you call your mother's brother's brother-in-law?

Count the number of triangles in the below picture?

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?