i need the methodology to solve questions like these.

8. John was saving $100 every month for one year. How much money is in his account two years after he stopped saving if he did not do any withdrawals in the last three years? The interest is compounded monthly, the nominal interest rate is 7%. 9. Jane paid $1000 into her new account a year ago. Then she added to this $300 three months later and then she withdrew $200 three months ago. How much money is in her account now? The interest is compounded monthly and the prorated interest rate is .5%. What is the nominal interest rate? 10. Hirunissa took a loan of $1000 from a bank one year ago. She paid back $300 four months ago. She plans to pay off the debt three months from now. What the single payment will be