"Combien sont-elles" est accepté ! Ça devrait être rejeté puisque le portugais pour cela serait "Quantas sao", non ?
This doesnt make sense. The portuguese phrase doesnt specify an object, so why the french answe should be elles, it is confusing and arbitrary.
Actually, it does. When , in portuguese, we use "quantos" we are saying that the subject is male. For female, we use the word "quantas". Therefore, the correct answer would be with "ils". I think Duo has made a mistake in this case, 'cause it has already happened in this lesson.