Final answer:
To calculate the percentage of profit, divide the profit by the total cost and multiply by 100.
Step-by-step explanation:
To calculate the percentage of profit, we need to find the total cost and total selling price of the lots.
The total cost of the two lots is $36,000 * 2 = $72,000. The total selling price of the three lots is $30,000 * 3 = $90,000.
To find the profit, we subtract the total cost from the total selling price: $90,000 - $72,000 = $18,000.
To calculate the percentage of profit, we divide the profit by the total cost and multiply by 100: ($18,000 / $72,000) * 100 = 25%.