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

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.

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

Fate has decided that you will only be pleased to meet me when you need me

Maybe that is why, when I am working, I start working

However annoying I may be to the regulars, the little ones are always inspired

I will always be waiting if you try to reach me

How many of you can guess my name, let me see

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

Spot 5 differences in two Christmas tree below:

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?