Question

plzzzzzzz give answer of 17.

Answer 1

u = speed of light in vacuum/ speed of light in medium

=> speed of light in medium = speed of light / u

therefore
speed of light in medium is indirectly proportional to u (refractive index).

Answer 2

hey friend

$n= \frac{c}{v}$

so, speed of light is directly proportional to the refractive index of any medium

so the light would travel more faster in Y