Why is the Hole below a Lock?

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

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

Can you place three balls such that the equation shown in the picture holds true?

I am the fastest animal but cannot climb the tree. What am I?

What do you answer even though it never asks you questions?

A game is being played where eight players can last for thirty-five minutes. Six substitutes alternate with each player in this game. Thus, all players are on the pitch for the same amount of time including the substitutes.

For how long is each player on the pitch?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?