XYZ Ltd is considering purchasing a new machine to improve its manufacturing process. The company has three options. The relevant details including estimated yearly expenditure and sales are given below. All sales are on cash basis. Corporate income-tax rate is 30%. Interest on capital may be assumed to be 9%.

Particulars	Machine X (Rs)	Machine Y (Rs)	Machine Z (Rs)
Initial investment	5,00,000	4,00,000	6,00,000
Estimated annual sales	7,00,000	6,50,000	8,00,000
Cost of production:
Direct material	60,000	55,000	70,000
Direct labour	70,000	60,000	75,000
Factory overhead	80,000	70,000	90,000
Administration cost	30,000	25,000	35,000
Selling & Distribution cost	20,000	15,000	25,000

The economic life of machine X is 4 years, while it is 3 years for the other two. The scrap values are Rs. 60,000, Rs. 50,000 and Rs. 70,000 respectively. Calculate the most profitable investment based on the payback period method.