The shape of water layer between the two plates is shown in the figure.
Thickness d of the film 
= 0.12 mm = 0.012 cm                
Radius R of cylindrical face$=\frac{\mathrm{d}}{2}.$
Pressure difference across the surface $=\frac{\mathrm{T}}{\mathrm{R}}=\frac{2\mathrm{T}}{\mathrm{d}}.$
Area of each plate wetted by water = A.
Force F required to separate the two plates is given by
F = pressure difference × area $=\frac{2\mathrm{T}}{\mathrm{d}}\mathrm{A}$
$=\frac{2\times 75\times 8}{0.012}={10}^5$ dynes