Answer asap

(a) A design company just purchased upgraded software for $6000 now and annual payments of $550 per year for 6years starting 3 years from now for annual up-grade. What is the present worth in year 0 of the payments if the interest rate is 8% per year compounded semi annually. (b) For the past 7 years, shell energy has paid $500 every 6 months for a software maintnce contract. What is the equivalent total amount after the last payment if these funds are taken from a pool that has been returning 8% per year