What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Find the last number in the series below:

voN luJ yaM raM ---

I look at you, you look at me, I raise my right, you raise your left. What am I?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

What does a man do only once in his lifetime, but women do once a year after they are 29?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

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

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

Can anyone explain, how is this possible?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?