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

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

Which tank will fill first?

I was speeding and ran through a stop sign, yet two traffic officers who were there do nothing about it.

why?

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

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?

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

I have branches, but no fruit, trunk or leaves. What am I?

Intelligence Agency need to break the vault but the problem is that they are not able to break the vault.

On the vault, a text is written as:

31 11 33 33 43 45
21 25
31 24 11 31 51 41

To Break the code Intelligence Agency brings a mathematician named Joseph.
Minutes later he deciphers the code.

Whats the code?