Galaxy B moves away from galaxy A at 0.577 times the speed of light. Galaxy C moves away from galaxy B in the same direction at 0.731 times the speed of light. How fast does galaxy C recede from galaxy A?

The value is  

Explanation:

From the question we are told that

   The speed at which galaxy B moves away from galaxy A is  

Here c is the speed of light with value  

     The speed at which galaxy C moves away from galaxy B is  

Generally from the equation of  relative speed we have that  

Here p is the velocity at which galaxy C recede from galaxy A so

=>  

=>  

=>  

=>  

=>    

see earlier answer