A bookstore owner sold 393 books in one week. She sold 1/3 as many books the next week. How many books did the store owner sell both weeks together?

Answer:The Answer is A
Step-by-step explanation:
The way I found this out is I rounded 393 to 400 and 1/3 of 400 is somewhere around 130 so it cant go over 600 because 400 + 130 = 530. so rounding to the nearest answer I got 524