input: Write a python function to calculate discounted cost based on the given cost and discount percentage.
  assert calculate_discounted_cost(100, 25) == 75.0
  assert calculate_discounted_cost(200, 50) == 100.0
  assert calculate_discounted_cost(50, 10) == 45.0
output: def calculate_discounted_cost(cost, discount_percentage):
      return cost - (cost * discount_percentage / 100)