Agamma ray has a very high frequency of about 1019 s-1. what is the wavelength of the gamma ray?

This is a relatively simple question given the formula and the important constant. The constant that we will need here is the speed of sound. That is 3.00*10^8 m/s. The speed of light is equal to the wave length times the frequecny. We are given the frequency and speed of light, wavelength is then computed as follows: 

wave length  = speed of light / frequency = 3.00*10^8 m/s/ 10^19 s-1 = 3*10^-11 m or 0.03 nm