How many sides does a circle have?

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

Replace the question mark with the correct number below.

Where do fish keep their money?

The following four words might seem abrupt to you. But you can make them meaningful by just adding vowels.
RDSH
GGPLNT
TMT
NN

Hint: All of them are vegetables.

You are given 16 witch hats. The hats are divided in four different colours – red, blue, green and yellow. Every colour has been assigned to four hats. Now each of the hat will be glued with a label of an arithmetic sign – ‘+’, ‘-‘, ‘x’ or ‘/’. But you can label one sign only once on one colour. In such an arrangement, the hats can be uniquely defined by its colour and symbol.

Can you arrange all the 16 hats in a 4x4 grid in a fashion that no two rows and columns have a repetition of colour or sign?
We have arranged four hats in the below picture to assist you.

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

How many triangles are there in the picture below?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

A man dies of old age on his 25 birthday. How is this possible?