The near vision of an average person is 25 cm

The near vision of an average person is 25 cm.
To view an object with an angular magnification of 10, what should be the power of the microscope?

The least distance of distinct vision of an average person is 25 cm in order to view an object with magnification of 10.
Here v = D = 25 cm and u = f
But the magnification, m=v/u = D/f
m = D/F
====>f=D/m=25/10 = 2.5=0.025m
P = 1/0.025 = 40 D
This is the required power of lens.