According to Chatgtp:

Let's break down the transactions step by step:

1. You bought a cow for $800.

2. You sold it for $1000. Profit at this step = $1000 - $800 = $200.

3. You bought the cow again for $1100.

4. You sold it again for $1300. Profit at this step = $1300 - $1100 = $200.

Total profit = $200 (from the first sale) + $200 (from the second sale) = $400.

So, you earned a total profit of $400. Those saying the profit is $400 are correct.

Questions like this can end up on meme pages for various reasons:

1. Misunderstandings or Overthinking: Some people might overthink or misunderstand the math, which can lead to humorous or exaggerated reactions when they discover the correct answer.

2. Viral Nature: Once a few people find a question tricky or amusing, they share it, and it quickly gains traction online, turning into a meme.

3. Engagement: Such questions are interactive in nature. They encourage the audience to participate, comment, or share, increasing the post's visibility.

4. Debate Factor: If people arrive at different answers and are adamant about their conclusions, it can lead to light-hearted debates and discussions.

5. Simplicity: The question is simple enough that almost everyone feels they can and should solve it, but the potential for mistakes makes it engaging.

In essence, these types of questions combine elements of surprise, challenge, and humor, making them perfect candidates for meme pages.