Please help me understand how to get he answers.

4. (0come) In 2018 there were three firms in an economy: A, B, and C. Firm A buys $500 worth of goods from firm B and $250 worth of goods from firm C and produces 200 units of output, which it sells at $15 per unit. Firm B buys $300 worth of goods from firm A and a $250 worth of goods from firm C, and produces 300 units of output, which it sells at $5 per unit. Firm C buys $250 worth of goods from firm A and nothing from firm B. It produces output worth $1,000. All other products are sold to consumers (10pts). a. dom) Calculate nominal GDP for this economy. What approach are you using? Show your calculations. b. (ipts) In 2019 we know that nominal GDP grew 3% with respect to 2018. What is the nominal GDP of 2019? c. (opte) If a value-added tax (a tax on the total value added of each firm) of 10 percent is introduced, how much revenue will the government get? d. (Code) How much would the government get if it introduced a 10% sales tax on final output? e. (Duty How much would the government get if it introduced a 10% income tax on final output