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

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

How old is your son? asked a man to his neighbour. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.

How old is the man's son ?

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

If you say my name, I will no longer exist. What am I?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

What two things can you never eat for breakfast?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?