What work can one never finish?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

It belongs to you, but other people use it more than you do. What is it?

Name a key which is hardest to turn.

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

John can eat 27 chocolates in an hour, Jacob can eat 2 chocolates in 10 minutes, and Jolly can eat 7 chocolates in 20 minutes. How long will it take them to share and eat a box of 120 chocolates whilst playing Chess?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

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