It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Why is Saturday stronger than Monday?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

What do you call a fish without an eye?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

What begins with T, ends with T, and has T in it?

A man walked into a pub and went straight towards the Barman. He asked for a dirty martini from the Barman. The Barman thought something and then pulled out a pistol from his drawer and aimed it directly at the man. Why did he do that?

Why did Navjot Singh Sidhu put the new January calendar in the freezer

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.