I am an odd number. Take away a letter and I become even. What number am I?

What does this mean?

CCCCCCC

Our product and our sum always give the same answer. Who are we?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

In the figure that has been attached to this question, each digit represents a digit. The similar letters carry the same integer value. Can you expose the original digits?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

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

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?