What of the three machines ABC Technologies should purchase?

ABC Technologies is considering the following three machines to make widgets. 1. Machine X costs $1,000,000, has 6 year economic life and a salvage value of $100,000. It will generate before tax cash flow of $400,000 (excluding CCATS) per year. 2. Machine Y costs $2,000,000, has 10 year economic life and a salvage value of $100,000. It will generate before tax cash flow of $600,000 (excluding CCATS) per year. 3. Machine Z costs $3,000,000, has 12 year economic life and a salvage value of $200,000. It will generate before tax cash flow of $790,000 (excluding CCATS) per year Whichever machine ABC purchases, it will keep repurchasing it forever. CCA rate is 30%, the corporate tax rate is 40% and the required rate of return is 15%.