input: Write a python function to create a Calculator class and compute the total and average of three numbers.
  assert Calculator(1, 2, 3).total() == 6
  assert Calculator(1, 2, 3).average() == 2.0
  assert Calculator(10, 20, 30).total() == 60
  assert Calculator(10, 20, 30).average() == 20.0
output: class Calculator:
      def __init__(self, num1, num2, num3):
          self.num1 = num1
          self.num2 = num2
          self.num3 = num3
  
      def total(self):
          return self.num1 + self.num2 + self.num3
  
      def average(self):
          return (self.num1 + self.num2 + self.num3) / 3