 
 <translate> Each of the four customers received delivery of 400 / 4 = 100 cartons of milk. Since each customer returned 60 cartons that were damaged during delivery, the number of cartons accepted is 100 - 60 = 40 cartons by each customer. If each customer accepted 40 cartons, the total number of cartons that the four customers did not return is 40 * 4 = 160. The final answer: 160. <hau> Kowane ɗayan abokan cinikin huɗu sun karɓi isar da 400 / 4 = akwatunan madara 100. Tunda kowane abokin ciniki ya dawo da kwali 60 waɗanda suka lalace yayin isarwa, yawan katunan da aka karɓa shine 100 - 60 = katunan 40 daga kowane abokin ciniki. Idan kowane abokin ciniki ya karɓi kwalaye 40, jimlar adadin kwalaye da abokan ciniki huɗu ba su dawo ba shine 40 * 4 = 160. Amsar ƙarshe: 160. 