What is the initial economic value of an annuity due if it consists of 19 semiannual payments

Question:

What is the initial economic value of an due if it consists of 19 semiannual payments of $1500? Money is worth 5% compounded semiannually for the first five years, and 6% com- pounded semiannually thereafter.
Annuity
An annuity is a series of equal payment made at equal intervals during a period of time. In other words annuity is a contract between insurer and insurance company in which insurer make a lump-sum payment or a series of payment and, in return,...