I have a really simple question that I can't figure it out. I have a process X that took 905 seconds to finish. Process Y took 950 seconds to finish. I want to know a) how much in % process X is faster than Y, and b) how much in % process Y is slower than X? I think that the answer is the following. a) Taking X as reference, X is faster (X-Y)/Y times. b) Taking Y as reference, Y is slower 1-(Y/X) times. Am I correct?