Answer:
(a) $45,000
(b) -$16,000
Explanation:
Accounting profits = Total revenue - Total costs
                = ($65 × 3,000) - (100,000 + 50,000)
                = $195,000 - $150,000
                = $45,000
Economic profits = Accounting profits - Opportunity cost
              = $45,000 - [$60,000 + (5% × $20,000)]
              = $45,000 - [$60,000 + $1,000]
              = $45,000 - $61,000
              = -$16,000                 Â