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

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

When can we add 2 to 11 and get 1 as the correct answer?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

Can you find out the missing number in the grid?

What am I?

In a certain country ½ of 5 = 3. If the same proportion holds, what is the value of 1/3 of 10?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?