Question

If refractive index of water w.r.t. air is 4/3 f then refractive index of air w.r.t. water will be

Answer 1

it will be reciprocal of  refractive index of water w.r.t. air

so it will be 3/4

Answer 2

refractive index of water w.r.t. air is 4/3

refractive index of air w.r.t. water =1/refractive index of water w.r.t. air

=1/(4/3)

=3/4