The first problem is from a 1984 IQ Test. Are you ready?

Here’s the scenario: A man buys a horse for $60, sells it for $70, buys it back for $80, and then sells it again for $90. The trick is to handle each transaction separately:

-60 + 70 = 10

-80 + 90 = 10

By doing this, we see that the man made $10 on each transaction. Therefore, his total profit is $20.

Did you come up with a different solution? Let us know your approach, and don’t forget to share this problem with your friends to test their skills!