Why is the longest human nose just 11 inches?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

Can you make a six-letter word using the letters N, A and B ?

How many words can a pen with half refill write?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?