Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside.
The man said, "Oh! I am really sorry, I thought this was my room."
He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man.
What made her suspicious of that man? He might have been genuinely mistaken.

What jumps when it walks and sits when it stands?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

What number should come in place of the question mark below?

On rolling two dices (six-sided normal dice) together, what is the probability that the first one comes up with a 2 and the second one comes up with a 5?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you make a six-letter word using the letters N, A and B ?

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?