Please answer question b thank u

1. (a) A pension fund manager knows that the following liabilities must be satisfied: Suppose that the pension fund manager wants to invest a sum of money that will satisfy this liability stream. Assuming that any amount that can be invested today can earn an annual interest rate of 7.6%, how much must be invested today to satisfy this liability stream? b) How much must be invested today if the interest rate is the same but the liabilities stream is changed to the following table