Lizzy: Ali had a stock of 800 books in his Room. He sold 60 on Monday, 10 on Tuesday, 20 on Wednesday, 44 on Thursday and 66 on Friday. How many books were not sold?.
Me: Hmmm, let me think. I think this is the detailed solution:
We look first for the total number of books that were sold: 60 + 10 + 20 + 44 + 66 = 200 books. So the total number of books that were not sold is: 800 200 = 600 books. Final answer: 600.