Please help me find the attached answers with formula and explanation.

Question 4 (30 marks) Your parents wish to save $30,000 for your wedding scheduled on 31 / 12 / 2022. They will start the rst monthly deposit by the end of this month, on 30/6/2021 and earn 5512 = 6% pa. (a) What is the regular deposit required per month? [1'0 marks] (b) Suppose that, after ve deposits, the interest rate falls to 3'12 : 2%. Determine the new deposit size required to meet the original target of $30,000. [20 marks]