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

Why is 6 afraid of 7?

How many triangles are there in the picture below?

Why do we preferably have round manhole covers and not square ones?

John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3

What does below pictogram mean?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

What goes up but never comes down?