Replace the question mark with the correct number in the below-given picture?

The chance of Mr John winning the lottery is 10%. All participants lined up and Mr John is 4th in the row. The first three participants lose the lottery.

What is the chance of Mr John now?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

What has one eye, but can’t see?

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

How many Watermelons are there in the below picture?

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

Can you convert the number zero(0) into a positive number using just one mathematical operator ?