 <translate> With her savings, Sara bought two books: a book for 5.5£ and a book for 6.5£. She gives a 20£ bill to the seller. How much change does she get back? Give me reasons, before answering the question <yor> Owó tó fi pa mọ́ ni Sara fi ra ìwé méjì, ìwé kan jẹ́ £5.5 èkejì sì jẹ́ £6.5. Ó fún oníṣòwò náà ní owó £20. Báwo ni iye tí wọ́n fún un ṣe pọ̀ tó? Sọ ìdí tó o fi ṣe é, kó o tó dáhùn ìbéèrè mi. 