Answer:
= $62 billion
Step-by-step explanation:
Since the country started year 1 with no public debt,
The country's debt at the end of year 5 = $50 (deficit year 2) + $30 (deficit year 3) - $20 (surplus year 4, negative deficit) + $2 (deficit year 5)).
= $62 billion
The country's debt at the end of year 5 = $62 billion
Public debt is the sum of deficits and surpluses (negative deficits) over time.