#3 is the correct answer.
First of all, the cost should be on one side and the earning on the other.
Eduardo needs to pay 7500 dollars plus 300 dollars a week, or 7500+300w
He earns 850 dollars, or 850w.
Now, we want him to make a profit, so 850w has to be greater than 7500+300w, so #3 is correct.
You are very welcome!
:P