We do not know yet. We do not have instruments that can tell which stars everywhere that have planets and which cannot. We can only tell within a couple hundred light years at that time and can only detect bigger planets.
At this time the answer is: We do not know yet but mankind is working on it.
Probably almost every star has its own solar system. So there are almost as many solar systems as there are stars. Which is billions and billions.
There may very well be an infinite amount.
There's at least an indefinite amount.
It's in the quadrillions, at minimum, and there's most likely quadrillions more than that.
1 for every star.
No one would know how many. People can take a guess and if you are comfortable with their numbers then go for it.
3.14 approximately.
more then sand grains on all the beaches
