Hint for Question 3
It would take 150 years to count how old Earth is (one number/per second).
Billions of years (thousands of millions) are needed, but don't go too low or too high.
This hint opened in a full-sized browser window because your browser either does not support scripting or you have turned scripting off. You might try making the window smaller manually and leaving it open. This way, hints will open in that smaller window.