It would be helpful to point out the use of could as well as would. Yes, there is one example using could, but for me at least, this didn't sink in until just now, and I have a high score on this lesson. More examples, plus pointing this out in the body of the lesson would be very useful.
The one example:
S'ils économisaient plus, ils pourraient se permettre des vacances.
If they saved more, they could afford holidays.