On a excel sheet model each question

7. You currently have $5000 in a savings account that pays 0.5% interest each month. You add another $200 each month.

8. You owe $500 on a credit card that charges 1.5% interest each month. You pay $50 each month and you make no new charges.

9. Your parents are considering a 30-year, $200,000 mortgage that charges 0.5% interest each month. Formulate a model in terms of a monthly payment p that allows the mortgage (loan) to be paid off after 360 payments. Hint: If an represents the amount owed after n months, what are a0 and a360?

10. Your grandparents have an annuity. The value of the annuity increases each month by an automatic deposit of 1% interest on the previous month's balance. Your grandparents withdraw $1000 at the beginning of each month for living expenses. Currently, they have $50,000 in the annuity. Model the annuity with a dynamical system. Will the annuity run out of money? When? Hint: What value will and have when the annuity is depleted?