Can you find out which number multiplied by itself will give the output as 12345678987654321?

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

It begins where the time ends.
Its second is an expression of surprise.
Its third is a question.
Its fourth is urinate.
It ends with a drink.

Which country it is?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

What famous saying does this rebus mean?

COME SERVED <---
COME SERVED
COME SERVED
COME SERVED
COME SERVED

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

How could a baby fall out of a twenty-story building onto the ground and live?