Two full turns of circular scale of a screw gauge cover a distance of 1 mm on its main scale.  The total number of division on the circular scale is 50. Further, it is found that are the screw gauge has a zero error of -0.03 mm. while measuring the diameter of a thin wire, a student  notes the main scale reading of  3 mm and the number of circular scale division, in line with the main scale, as 35. The diameter of the wire is $\frac{338}{20\mathrm{n}}\mathrm{mm}$ find the value of ‘n’