Answer: What do you need, what grade are you in?
Step-by-step explanation:
I believe 9. I divided 200 books among 24 boxes and got 8.3333..., so that means there would be 8 full boxes plus 1 not full boxes which means that there are 9 boxes total.
There were 200 books sold. so, they need to sell 300 more to have 500 total books sold.