What do you get if you add 2 to 100 four times?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Which is the rope you never skip with?

What is the coolest letter in the alphabet?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

12345 a famous South Indian actor
567 is a path in jumbled form
8 & 10 are same letters
9 is one among the first six alphabets.
WHO AM I?

When it's bad luck to meet a black cat?

What breaks yet never falls, and what falls yet never breaks?