Answer:
32.1
Step-by-step explanation:
NOTE: You did not state the angle of incidence, and thus, I will be using 45° as my angle of incidence, all you need to do is replace it with your own value if it's different.
To solve this question, we are going to be using Snell's Law.
Snell's law describes the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.
Snell's law is mathematically given as
sin(A1)/sin(A2) = n2/n1, where
n1 = incidence index
n2 = refracted index
A1 = incidence angle
A2 = refracted angle
The refraction index of oil is 1.15, and that of water is 1.33, so
if we take oil first,
sin A2 = (n1.sinA1)/n2
sin A2 = (1 * sin 45)/1.15
sin A2 = 0.7071/1.15
sin A2 = 0.6149
A2 = sin^-1 0.6149
A2 = 37.9°
Then
sin A3 = (1.15 * sin 37.9) / 1.33
sin A3 = (0.6149 * 1.15) / 1.33
sin A3 = 0.7071 / 1.33
sin A3 = 0.5317
A3 = sin^-1 0.5317
A3 = 32.1