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?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

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

During an interview, the interviewer ordered hot coffee for the candidate to relieve the stress. The coffee was kept before him. After a minute, the interviewer asked him, 'What is before you?' He replied 'Tea'.

The candidate was selected immediately. Why?

What does it mean?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

You order chicken wings at KFC in the boxes of 6, 9 and 20. What is the largest number of wings that you cannot obtain by buying in any combination of the boxes?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

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

What brings you down but never up?