Can you solve this picture maths equation?

what does this below rebus represent identXQQQQQME

How many letters are in the alphabet?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Can you write down eight eights so that they add up to one thousand?

What is the centre of gravity?

In the picture that is attached with this question, you can find a square which comprises of four little squares inside it. Consider this square to be made with matchsticks. You have to remove two matchsticks such that only two squares remain instead of five.How will you do it ?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?