What will be its new frequency?

Case : Read the passage and answer the question(s).

The properties of a light such as its speed, frequency and wavelength and properties of the medium like its refractive index give us a lot of information about the interaction of light with that medium. Consider a monochromatic ray of light travelling in vacuum with speed c, wavelength λ and frequency v, enters into a medium of refractive index 1.5.