input: def generate_multiplication_table(start, end):
      """Generate a multiplication table for numbers in the given range.
      >>> generate_multiplication_table(5, 10)
      '25  30  35  40  45  50  
      30  36  42  48  54  60  
      35  42  49  56  63  70  
      40  48  56  64  72  80  
      45  54  63  72  81  90  
      50  60  70  80  90  100  
      '
      """
      result = ""
      for x in range(start, end + 1):
          for y in range(start, end + 1):
              result += str(x * y) + "  "
          result += "\n"
      return result
output:     result = ""
      for x in range(start, end + 1):
          for y in range(start, end + 1):
              result += str(x * y) + "  "
          result += "\n"
      return result