Anna’s story begins with a straightforward series of transactions involving a cow.

Initially, she bought the cow for $100. Sensing an opportunity, she decided to sell it shortly afterward, managing to make a sale at $120. At this point, Anna had already made a $20 profit.

But the story didn’t end there. Later, Anna decided to buy back the cow, this time at a higher price of $150. This move temporarily put her at a $30 loss since she initially sold it for $120 and then bought it back at a higher price.

Anna didn’t give up. She saw another opportunity and sold the cow again, this time at $170. By selling it for $170, she made a $20 profit from this transaction alone, covering her earlier $30 loss and adding an extra $20 profit overall.

When all transactions were completed and the math was done, Anna came out ahead. Her total profit was $40. She made $20 from the first sale and another $20 from the second sale.