What number when divided in half becomes zero?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

The Puzzle: A girl, a boy, and a dog start walking down a road.

They start at the same time, from the same point, in the same direction.

The boy walks at 5 km/h, the girl at 6 km/h.

The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn.
How far does the dog travel in 1 hour?

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

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

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 have no life, but I can die. What am I?

My location can be determined by the below rebus.
So where am i ?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?