Which number should replace the question mark?

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

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

What is always in front of you but can’t be seen?

Different lights make me strange by changing me into different sizes. What am I?

On rolling two dices (six-sided normal dice) together, what is the probability that the first one comes up with a 2 and the second one comes up with a 5?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

I cannot talk, but I always reply when spoken to. What am I?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?