1.2 Suppose you are offered an investment that will allow you to double your money in 9 years. You have R20 000 to invest. What is the implied rate of interest? (7) 1.3 Suppose you have a 4-year-old son and you want to provide R55 000 in 16 years towards his college education. You currently have R5 000 to invest. What interest rate must you earn to have the R55 000 when you need it? (7) 1.4 Suppose you want to buy a new house. You currently have R30 000 and you figure you need to have a 10% down payment plus an additional 5% of the loan amount in closing costs. If the type of house you want costs about R450 000 and you can earn 7.5% per year, how long will it be before you have enough money for the down payment and closing costs? (6)