Final answer:
To calculate the percentage of profit based on the investor's cost, we need to determine the difference between the cost price and the selling price of the property, and then calculate the percentage of that difference in relation to the cost price.
Step-by-step explanation:
To calculate the percentage of profit based on the investor's cost, we need to determine the difference between the cost price and the selling price of the property, and then calculate the percentage of that difference in relation to the cost price. Let's assume the listed price of the property was $100. The investor purchased it at 20% less, which means they bought it for $80. If they later sold the property for $100, the difference between the selling price and the cost price is $100 - $80 = $20. To calculate the percentage of profit based on the cost price, we divide the difference by the cost price and multiply by 100: ($20 / $80) * 100 = 25%. Therefore, the investor made a 25% profit based on their cost.