Please assist with the below questions

2.1 Your parents set up a trust fund for you 20 years ago that is now worth R40 671,51. If the fund earned 9% per year, how much did your parents invest? 2.2 Suppose you are offered an investment that will allow you to double your money in 8 years. You have R12 000 to invest. What is the implied rate of interest? 2.3 Suppose you have a 1-year old son and you want to provide R92 000 in 18 years towards his college education. You currently have R8000 to invest. What interest rate must you earn to have the R92 000 when you need it? 2.4 Suppose you want to buy a new vehicle. You currently have R15 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 vehicle you want costs about R150 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