5. What would the annual total cost for this business be?

TC = hired cost + sons cost + managerial cost = 50,000

6. What would the annual accounting profit for this business be?

Accounting Profit is TR – Explicit Costs (hired labor and purchased supplies)
Therefore Accounting Profit = 100,000 – 70,000 (20,000 +50,000) = 30,000

7. What would the annual economic profit for this business be?

Economic Profit is TR – (Explicit Costs + Implicit Costs)
In this case, implicit cost is the sons labor cost and your managerial cost. Therefore Economic Profit = 100,000 – 100,000 (70,000 + 30,000) = 0

8. What would the annual normal profit for this business be?

Normal profit is zero as above.
Should supplies have been 40,000, then abnormal profit would have been 10,000.
Should supplies have been 60,000, then economic profit would have been - 10,000.