Answer
The frequency of the mentioned light is $\nu\approx9.369\times10^{14}s^{-1}$
Work Step by Step
The frequency of light is calculated according to the formula $$\nu=\frac{c}{\lambda}$$
$\nu$: frequency of light
$c$: speed of light in vacuum $(c\approx2.998\times10^8m/s)$
$\lambda$: wavelength of light
Here the wavelength of light $\lambda=320nm=3.2\times10^{-7}m$
So, the frequency of light is $$\nu=\frac{c}{\lambda}$$$$\nu=\frac{2.998\times10^8m/s}{3.2\times10^{-7}m}\approx9.369\times10^{14}s^{-1}$$