Presley is organizing the school book sale. Each stall will have 40 books on the shelf and 2 boxes of books with b books inside. Presley also has 200 books in inventory to refill the shelves as books

Presley is organizing the school book sale. Each stall will have 40 books on the shelf and 2 boxes of books with b books inside. Presley also has 200 books in inventory to refill the shelves as books sell. This situation can be written as the following expression:

40s + (2b)s + 200

How many books should Presley have ready if she plans to open 8 stalls and have 12 books in each box?

A) 520 B) 712 C) 820 D) 1,622