Fill in the blank with the correct number. Mark had 50 books at first.He gave (1)/(5) of his books to his best friend.Then he gave (3)/(10) of the remaining books to his brother.How many books does he have now? Answer: He has square books.

Mark gave of 50 books to his friend, which is books. He had books remaining.Then he gave of the remaining 40 books to his brother, which is books.He has books left.Answer: 28