why number 8549176320 is one of a kind?

What can you serve, but never eat?

What's the only room from which no one can enter or leave

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?

If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

What does it mean?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Can you name four days which start with the letter 'T'?