1. The problem statement, all variables and given/known data I encountred a question that says : Assume that gravitational interactions between galaxies in groups lead to random galaxy velocities of 300 km/s At what distance would the redshift predicted by Hubble's law dominate over that produced by individual velocities? and what is the redshift at that distance? I don't understand whats the difference between the 2 redshifts mentioned here, so I am confused on how to approach this 2. Relevant equations V= h_0 * D where D is the distance and the hubble constant is 2.18*10^-18 s^-1 V /c = Δλ/λ 3. The attempt at a solution I tried substituting in the numbers and got D= 1.36*10^20 km and v/c=0.001.