i$.$ if Cost $=$$$40,000$;$CF=$$$15,000$ per year for $3$ years, calculate the payback period $(2$ marks$)$

ii$.$ Let's say that the owner of Perfect Images Salon is considering the purchase of a new tanning bed. It costs $$10,000$ and is likely to bring in after$-$tax cash inflows of $$4,000$ in the first year, $$4,500$ in the second year, $$10,000$ in the $3^{rd}$ year, and $$8,000$ in the $4^{th}$ year. calculate its NPV and indicate whether the investment should be undertaken or not. The cost of capital is $10\%.(2$ marks$)$