1.21 × 10^−7 / 2.998 × 10^8
Looks like you got it backward!!
Frequency = Speed of light / Wavelength.
Frequency = [2.998 x 10^8] / [1.21 x 10^-7]
Frequency =2.4777 x 10^15 Herz or Hertz!!.
Appreciate the help, sorry i got it the wrong way around! I just looked it up again and seen my mistake. thank you again.