Please show a step by step solution with the general equations and the numbers plugged into the equations. No excel please!

Recent technology has made possible a computerized vending machine that can grind coffee beans and brew fresh coffee on demand. The computer also makes possible such complicated functions as changing $5 and $10 bills and tracking the age of an item and then moving the oldest stock to the front of the line, thus cutting down on spoilage. With a price tag of $4,500 for each unit, Easy Snack has estimated the cash flows in millions of dollars over the product's six-year useful life, including the initial investment, as follows: Net Cush Flow -$20 $8 $17 au A WN - o $19 $18 $10 (a) If the firm's MARR is 18%, is this product worth marketing according to the IRR criterion? (b) If the required investment remains unchanged but the future cash flows are expected to be 10% higher than the original estimates, how much increase in IRR do you expect