Answer: 23.

**Explanation:** In perfect competition, a firm maximizes profit where Marginal Revenue (MR) equals Marginal Cost (MC). Since this is perfect competition, price is constant and equal to MR. From the table: - Price = Total Revenue / Quantity = $210/21 = $10 per unit **Calculating Marginal Revenue and Marginal Cost:** 1. **From 21 to 22 units:** - MR = ΔTR/ΔQ = ($220 - $210)/(22-21) = $10 - MC = ΔTC/ΔQ = ($145 - $138)/(22-21) = $7 - Profit increases by $3 ($10 - $7) 2. **From 22 to 23 units:** - MR = ($230 - $220)/(23-22) = $10 - MC = ($154 - $145)/(23-22) = $9 - Profit increases by $1 ($10 - $9) 3. **From 23 to 24 units:** - MR = ($240 - $230)/(24-23) = $10 - MC = ($165 - $154)/(24-23) = $11 - Profit decreases by $1 ($10 - $11) **Calculating Total Profit at each output level:** - At 21 units: Profit = $210 - $138 = $72 - At 22 units: Profit = $220 - $145 = $75 - At 23 units: Profit = $230 - $154 = $76 - At 24 units: Profit = $240 - $165 = $75 The maximum profit is $76 at 23 units. The firm should produce 23 units because: - At 23 units, MR ($10) > MC ($9), so producing more would increase profit - At 24 units, MR ($10) < MC ($11), so producing the 24th unit would reduce profit Therefore, the profit-maximizing output is 23 units.

Author: LeetQuiz .