What goes up but never comes down?

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.
Now all your friends have one apple each, yet there is an apple remaining in the basket.
How?

Can you place three balls such that the equation shown in the picture holds true?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

Can you name some countries which do not have the alphabet 'A' in them?

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

which number am I?

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.

There is something which you can be arrested for attempting but not for successfully completing.

I am quite hot but become too cold if you remove the first two letters. What am I?

I look at you, you look at me I raise my right, you raise your left. What am I?