
Refractive index of a medium nm is related to the speed of light in that medium v by the relation:
\(n_m = \frac{\text{Speed of light in air }}{\text{Speed of light in the medium }}= \frac{c}{ v}\)
Where, c is the speed of light in vacuum/air. 
The refractive index of diamond is 2.42. This suggests that the speed of light in diamond will reduce by a factor 2.42 compared to its speed in air.
Two light beams fall on a transparent material block at point 1 and 2 with angle \( \theta_1 \) and \( \theta_2 \), respectively, as shown in the figure. After refraction, the beams intersect at point 3 which is exactly on the interface at the other end of the block. Given: the distance between 1 and 2, \( d = 4/3 \) cm and \( \theta_1 = \theta_2 = \cos^{-1} \frac{n_2}{2n_1} \), where \( n_2 \) is the refractive index of the block and \( n_1 \) is the refractive index of the outside medium, then the thickness of the block is cm. 
The following data shows the number of family members living in different bungalows of a locality: 
 
| Number of Members | 0−2 | 2−4 | 4−6 | 6−8 | 8−10 | Total | 
|---|---|---|---|---|---|---|
| Number of Bungalows | 10 | p | 60 | q | 5 | 120 | 
If the median number of members is found to be 5, find the values of p and q.