Answer: $15,000
As $35,000-$20,000=$15,000.
That's basically the profit he had made, or the return on his investment (ROI).
As he already had $20,000, he had "only" made $15,000.
Andrew invested $20,000 and received $35,000, leading to a profit of $15,000. The Return on Investment (ROI) is calculated as 75%. This means Andrew earned 75% more than his initial investment.
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