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

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

Can you decipher the two rows to find the hidden word?

A clock loses 10 minutes each hour. If the clock is set correctly at noon, what time is it when it reads 3 PM?

Can you write down eight eights so that they add up to one thousand?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?