What is the fastest way to double your money?

Look at the picture and find out which square is not linked with any of the other squares.

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

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.

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

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

What can you serve, but never eat?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

If EELS + MARK + BEST + WARY = EASY

What does HELP + BARK + WARD + LEAD equal?