The speed of light in air is 3 x 10^{8} m/s. In medium ‘X’ its speed is 2 x 10^{6} m/s and in medium ‘Y’ the speed of light is 2.5 x 10^{6} m/s. Refractive index of ‘Y’ with respect to ‘X’ is

The speed of light in air is 3 x 10^{8} m/s. In medium ‘X’ its speed is 2 x 10^{6} m/s and in medium ‘Y’ the speed of light is 2.5 x 10^{6} m/s. Refractive index of ‘Y’ with respect to ‘X’ is