Can you calculate the probability of getting a sum of six when a dice is thrown twice?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

O_er_t_o_

Complete the missing letters of the given word.

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

81 x 9 = 801. What must you do to make the this equation true?

What part of the chicken has the most feathers?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

I am a five-letter word under you,
Remove the first letter and I am above you,
Remove the second as well and I am around you.

Who am I?