There is not enough information given to answer with. The force of gravity at the planet's surface depends on the planet's radius as well as its mass. The planet could have exactly the same mass as Earth has. But if it's radius is only 71% of Earth's radius, then gravity on its surface will be twice as strong as gravity on Earth.
Start by using the addition as a sign and use multiplying
Hope this helps, if you need clarification i got you
That's a loaded question. Well to me, through what I have heard from others and theories, I imagine there was other universes before us. It wasn't just nothingness, there was another universe, perhaps in another dimension that either ended or is still around today. Alternate dimensions are a theory, so it was probably just a matter of when ours would be born. We could've been the result of reaching the singularity in a black hole or we could've been the continuation of a grand generation of universes. Either way, I think before us there was other things that filled the void of darkness that we imagine to be before us.