Peter want to purchasing his first car, which have estimated will cost $30,000 in three years. You currently have $5,000, which is not enough for your target. As an incentive for good grades in his course, Peter's parents are proposing that they provide Peter with a lump sum at the end of each semester depending on the average grade over the semester. They will pay Peter the following amount at the end of each semester (2 semesters per year) for each of the grades: HD get $ 5000. D get $4000, C get $3000 and Pass 1 and 2 get $2000. Peter's $5,000 currently sits in a 6-month term deposit account that pays 6% per annum, compounding 6 monthly.Peter will place the money provided by his parents into this term deposit at the end of each semester to gain interest. If peter can keep his grade during whole academic career. What grade he will need to maintain to buy the car at the end. Please show the detail of the calculation.