Multiply Time in C#

  string a = "8:25";

  int n = 2;//multiply by

  string[] time = a.Split(':');

  string output = string.Empty;

  int c = (int.Parse(time[0]) * 60 + int.Parse(time[1])) * n;

  if (c % 60 == 0)

     { output = (c / 60).ToString(); }

  else

     output = (c / 60).ToString() + ":" + (c % 60).ToString();