How long would it take a radio wave with

a frequency of 5.1 × 105 Hz to travel from
Mars to Earth if the distance between the two
planets is approximately 8.00 × 107 km?

1 answer

unless you want to know the wavelength, the frequency does not matter.

t = d/v = 8.0*10^7 km / 3*10^5 km/s = 266.7 s