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?

Forwards I am heavy, backward I am not. What am I?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?

When I asked a girl's name she told me her name is the date '07/09/2001'.

I thought for a few seconds and then I got her name. Do you?

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)