What number should come in place of the question mark below?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

When it is alive we sing, when it is dead we clap our hands. What is it?

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

Can you find the least possible number such that

If the number is divided by 3, it gives the remainder of 1;
If the number is divided by 4, it gives the remainder of 2;
If the number is divided by 5, it gives the remainder of 3;
If the number is divided by 6, it gives the remainder of 4.

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

Which is faster, Heat or Cold ? Explain.

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?