Use the open numbers to flag every mine in the field — every puzzle can be solved by logic, without guessing.
The full guide, with a worked example and common mistakes: How to play Mine Finder.
No — every puzzle is generated and checked so that each mine can be found by logic.
It has no mines among its eight neighbours.
Yes — every puzzle here has exactly one solution.
Yes — open the Mine Finder Solver, type the open numbers and the mine total, and press Solve.