I look at you, you look at me, I raise my right, you raise your left. What am I?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

It is always ahead of me yet I can never see it. What is it?

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?

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

What is so fragile that saying its name breaks it?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What goes up but never comes down?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?