 
 <translate> Dexter have 9 x 15 = 135 basketball cards. He filled 9 - 3 = 6 plastic boxes with football cards. So, he has 6 x 20 = 120 football cards. Therefore, Dexter has 135 + 120 = 255 cards in total. The final answer: 255. <hau> Dexter yana da katunan kwando 9 x 15 = 135. Ya cika akwatunan filastik 9 - 3 = 6 da katunan kwallon kafa. Don haka, yana da 6 x 20 = 120 katunan kwallon kafa. Saboda haka, Dexter yana da katunan 135 + 120 = 255 a duka. Amsar ƙarshe: 255. 