Ibn Jurayj (may Allah have mercy on him) said: I asked Ata' (may Allah have mercy on him) about a group of partners who have forty goats in common. He said: There is one goat (due) on them. He said: I said: What if one of them has thirty-nine and the other has one goat? He said: There is only one goat (due) on the two of them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7336