Answer:
1) this country's public debt = $42 billion
2) incomplete question
Explanation:
A budget deficit is the difference between a country's income and its expenditures, a deficit occurs when expenditures are larger than revenues. The public debt would be the accumulation of all the country's budget deficits or surpluses.
public debt = -$20 - $30 + $10 - $2 = -$42 billion