please please answer both questions urgently and perfectly. mention each question answer as you give. make sure to give correct answer

estion 7 We looked at some present and future value tables. What does using the tables take the place of? O a. Understanding future value O b. Using the formulas for present and future value O c. Doing calculations O d. Understanding present value estion 8 2 points I have $100 to invest and there's a CD with a 196 interest rate. If I put my money in and leave it alone, how many years will it take to double my money