Refractive index (n) = 1.33
Speed of light in air = 3x 108 ms-1
Speed of light in water = ?
The refractive index is given by n= c / v
Substituting the given values in the above equation, we will get
v = c / n
= 3×108 m/s / 1.33
∴ v = 2.25×108 m/s
So, the speed of light in glass would be 2.25×108 m/s.