At the bookstore, Sarah bought 6 paperback books and 4 hardback books. Her brother bought one-third as many paperback books as Sarah bought, and two times the number of hardback books that she bought. How many books did her brother buy in total?
Please answer the following question by reasoning step-by-step.
10
Her brother bought 6 / 3 = 2 paperbacks.

He bought 4 * 2 = 8 hardbacks.

In total he bought 2 + 8 = 10 books.

.

The final answer: 10