Find a frequency of blue light

It can be easy solved with simple formula - frequency = c/λ

λ = 464nm = 4.64 x 10^{-7} m

speed of light = c = 3 x 10^{8} m/s

frequency = c/λ = 3 x 10^{8}/4.64 x 10^{-7} = 6.46 x 10^{14}