Translation:Describe the goal and length of your stay.
As others mention here, we just don't speak of the "goal" of a stay in English. It's "purpose". Amongst many really awful lessons at this level of French, where it's very difficult to get the system to accept even the best English translations, I have to say that this is one of the worst. The person who wrote this chapter does not have the language skills to be writing any of these English sentences. PERIOD. It makes the process maddeningly frustrating for a native English speaker to learn French. Despite many people here continuously begging Duo to address this problem, we are ignored. Really says something about the quality.