Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

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?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

I am white when I am dirty, and black when I am clean. What am I?

How many letters are in the alphabet?