What is the riddle which can be asked all day with a different correct answer each time.

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don't know which is which.
What is the question you ask?

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

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

How many times in a given day, minutes and hour clock comes in a straight line ?

Find the next number in the series.
1 10 24 43 67 ?

Below, you can see some coding:
January = 1017
February = 628
March = 1335
April = 145
May = 1353
June = 1064
July = 1074
August = 186

Now deciphering the way it has been coded, can you find out how September will be coded?

How can a man go eight days without sleep?