For the given cash flows, suppose the firm uses the NPV decision rule. a. At a required return of 10 percent, what is the NPV of the project? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. At a required return of 20 percent, what is the NPV of the project? (A negative answer should be indicated by a minus sign. Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.)