i am struggling with this question can someone help me

Exercice 2: a. A company wants to provide a retirement plan for an employee who is aged 55 now. The plan will provide her with an annuity-immediate of $7,000every year for 15 years upon her retirement at the age of 65. The company is funding this plan with an annuity-due of 10 years. If the rate of interest is 5%, what is the amount of installment the company should pay? b. Find the present value of an annuity-due of $200 per quarter for 2 years, if interest is compounded monthly at the nominal rate of 8%. c. Find the present value of an annuity-immediate of $100 per quarter for 4 years, if interest is compounded semiannually at the nominal rate of 6%