If eleven plus two equals one, what does nine plus five equal?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

What demands an answer, but asks no questions

How many times can you subtract the number 5 from 25?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

In an interview, a boy was asked an unusual question 'How two persons sitting with a table in between them can't see each other?' He was unable to reply. Can you?

A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log.

Can you calculate the weight of the entire wooden log?

Fate has decided that you will only be pleased to meet me when you need me

Maybe that is why, when I am working, I start working

However annoying I may be to the regulars, the little ones are always inspired

I will always be waiting if you try to reach me

How many of you can guess my name, let me see

What breaks yet never falls, and what falls yet never breaks?