Answer:
1.75
Step-by-step explanation:
refractive index of oil, n1 = 1.46
angle of incidence, i = 67°
angle of refraction, r = 50°
Let the refractive index of unknown liquid is n2.
According to Snell's law
Refractive index of medium 2 with respect to medium 1 = Sin i / Sin r
Here medium 1 is oil and medium 2 is unknown liquid.



n2 = 1.75
Thus, the refractive index of unknown liquid is 1.75