C. For every decrease of one chore completed, one hour was spent on the internet.
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.
56.25 minutes
Explanation: to find how long it takes to run one mile, divide 50 minutes by 8 miles.
50/8 = 6.25
Then you can multiply 6.25 by 9 to find the answer.
9 x 6.25 = 56.25 minutes