I bought a cow for 800 I sold it for 1,000 I bought it again for 1,100 I sold it again for 1,300 how much did I earn

Answer 1

You earned a total of $400.

Here's the breakdown:
Bought cow for $800 and sold it for $1000, earning $200
Bought cow again for $1100 and sold it for $1300, earning another $200

$200 + $200 = $400 earned in total.