ABC Manufacturing Co. is planning to buy a new machine to improve production efficiency. Three machines are available for consideration. The details are as follows. Assume all sales are on cash. The corporate income-tax rate is 30%. Interest on capital may be assumed to be 11%.

Particulars	Machine X(Rs)	Machine Y(Rs)	Machine Z(Rs)
Initial investment	5,00,000	4,00,000	4,50,000
Estimated annual sales	6,50,000	5,50,000	5,80,000
Cost of production:
Direct material	70,000	65,000	60,000
Direct labour	55,000	45,000	50,000
Factory overhead	85,000	75,000	70,000
Administration cost	20,000	18,000	15,000
Selling & Distribution cost	12,000	10,000	8,000

The economic life of Machine X is 6 years, Machine Y is 4 years, and Machine Z is 5 years. The scrap values are Rs.30,000, Rs.25,000, and Rs.35,000 respectively. Determine the most profitable investment based on the payback period method.