If you say my name, I will no longer exist. What am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

What number do you get when you multiply all of the numbers on a telephone's number pad?

Why do we preferably have round manhole covers and not square ones?

The more of this there is, the less you see. What is it?

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

How can a man go eight days without sleep?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=