code: def range_minmax(ranges):
      
      rmin = min(ranges)[0]
      rmax = max(ranges, key=lambda x: x[1])[1]
      return rmin, rmax
docs: Returns the span of a collection of ranges where start is the smallest of
      all starts, and end is the largest of all ends.
  
      >>> ranges = [(30, 45), (40, 50), (10, 100)]
      >>> range_minmax(ranges)
      (10, 100)