Explanation

In a measurement instrument, the Main Scale Division (MSD) is the value of the largest division on the scale and Least Count (LC) is the smallest division on the scale that can be read with accuracy.

The number of equal parts in MSD 'n' is determined by dividing the MSD by the least count.

Given that one MSD = 2 mm and least count = 0.20 mm, To find the number of equal parts in the MSD, you can use the following formula:

Number of equal parts = MSD / least count = 2 mm / 0.20 mm = 10 parts

Therefore, there are 10 equal parts in the MSD 'n' in this case. This means that the scale is divided into 10 equal parts, each one with a value of 0.2 mm.