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

How many sides does a circle have?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Which five letter word can be added at the end of below word to form a
valid word?

> Pin
> Check
> Boiling
> View

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

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Look at me. I can bring a smile to your face, A tear to your eye, Or even a thought to your mind. But, I can't be seen. What am I?

There is something which you can be arrested for attempting but not for successfully completing.

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

0 0 0 = 6
1 1 1 = 6
2 2 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

You can use any mathematical symbols in the space provided to make all above algebraic expressions true.