(a) Rental costs for office space have been going up at 5% per year compounded semiannually for the past 4 years. If office space rent is now RM40 per square foot per month, what were the rental rates 4 years ago? [4 marks]

(b) Find the effective rate of interest corresponding to a nominal rate of 8% per year compounded

(i) semiannually, [3 marks]

(ii) monthly. [3 marks]

(c) Sally wishes to accumulate a sum of $400,000 in a retirement account by the time of her retirement 25 years from now. If she wishes to do this through monthly payments into the account that earn interest at the rate of 6% per year compounded monthly, what should be the size of each payment? [5 marks]

(d) John has RM50,000, 18 years mortgage at 7% compounded monthly. (i) Find the monthly payment? [5 marks]

(ii) Suppose John decide to add an extra RM50 to his mortgage payment each month starting from the very first payment. How long will it take John to pay off the mortgage?[5 marks]