new_contents: # The range of a set of values is the maximum value minus the minimum
  # value. Define a procedure, set_range, which returns the range of three input
  # values.
  
  # Hint: the procedure, biggest which you coded in this unit
  # might help you with this question. You might also like to find a way to
  # code it using some built in functions.
  
  def set_range(a, b, c):
      return max(a,b,c) - min(a,b,c)
  
  print set_range(10, 4, 7)
  #>>> 6  # since 10 - 4 = 6
  
  print set_range(1.1, 7.4, 18.7)
  #>>> 17.6 # since 18.7 - 1.1 = 17.6
  
subject: range of a ser solved