Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

Two fathers and two sons decided to go to a shop and buy some sweets upon reaching. Each of them bought 1 kg of sweet. All of them returned home after some time and found out that they had 3kg of sweets with them.

They did not eat the sweets in the way, nor threw or lose anything. Then, how can this be possible?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?