The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

I was speeding and ran through a stop sign, yet two traffic officers who were there do nothing about it.

why?

Find out which of the given views in the picture is accurately the top view of the given pyramid.

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

A beggar on the street can make one cigarette out of every 6 cigarette butts he finds. After one whole day of searching and checking public ashtrays the beggar finds a total of 72 cigarette butts. How many cigarettes can he make and smoke from the butts he found?

We are a group of eight brothers. We consider the weak, yet we protect the king in every battle. If we move ahead, we never turn back. Who are we?