Eye

If 65% of a population group have black eyes, 25% have brown eyes, and the remaining have blue eyes, what is the probability that a person selected at random has (i) blue eyes (ii) brown or black eyes (iii) blue or black eyes (iv) neither blue nor brown eyes

A : When viewing through a compound microscope, our eyes should be positioned not on the eye piece but a short distance away from it for best viewing. R : The image of the objective in the eye-piece is known as 'eye-ring' and if we position our eyes on the 'eye-ring' and the area of the pupil of out eye is greater or equal to the area of the eye ring, our eyes will collect all the light refracted by the objective.