The position of object and concave mirror is shown below.
Given, vreal=50‌cm and vappacrat=40‌cm The distance outside the transparent medium is, Dreal=vreal− thickness of transparent medium Dreal=50−20 Dreal=30‌cm The apparent distance is, Dapparent=(40−20) Dapparent=20cm The refractive index of the liquid is, µ=