can I please have the solution for this question

3. Midwest Bank offers a return of 5% compounded annually for each and every year. The rival BFB offers a return of 3% for the first year and 7% in the second and subsequent years (both compounded annually). Which bank would you choose to invest in if you decided to invest a principal for (a) two years; (b) three years? 4. A car depreciates by 40% in the first year, 30% in the second year and 20% thereafter. I buy a car for $14 700 when it is two years old. (a) How much did it cost when new? (b) After how many years will it be worth less than 25% of the amount that I paid for it