If I do, don't tell me what the mistake is; just say, "you're close," or something like that, and I'll try and figure out the answer -- which could be pretty entertaining in itself.
Si c'est le cas, ne me dites pas ce qui est erroné. Dites seulement, "c'est proche," ou quelque chose comme ça, et je vais tenter de trouver la réponse -- ce qui pourrait devenir intéressant.