Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

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?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

Why do you find that most of the buildings are deprived of the 13th floor?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

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