At first glance, this question looks confusing because the man buys and sells the same goat more than once. Many people start thinking he lost money when he bought it back for $80, because he paid more than the first time. But the easiest way to solve it is to separate the two deals.
In the first deal, he buys the goat for $60 and sells it for $70.
That means:
$70 – $60 = $10 profit
So, from the first transaction, he made $10.
Then he buys the goat again, this time for $80, and sells it again for $90.
That means:
$90 – $80 = $10 profit
So, from the second transaction, he also made $10.
Now we add both profits together:
$10 + $10 = $20
So the correct answer is:
He made $20.