By the definition, pressure is a physical quantity equal to the force divided by the area on which this force acts. It is supposed in this definition that the force acts perpendicularly to the surface. Also it is supposed that the force is uniform over the area. If not, this formula defines average pressure.
So `P = F/A,` where `P` is the pressure, `F` is the force and `A` is the area. In our problem `F` and `A` are given, thus we only need to divide:
`P = (25 N)/(25 cm^2) = 1 N/(cm^2).`
Such a unit, `N/(cm^2),` is possible for pressure, but isn't standard. In Si, the standard unit for length is meter (m), therefore `m^2` is used for area. In these units the answer is `1*10^4 N/m^2,` because there are `100 cm` in `1 m,` so there are `100*100 cm^2` in `1 m^2.`