Answer:
7 1/2 hours I believe is the correct answer. Hope it works!
The answer to the question that needs to go on the top is 33
Ok so we know he used over 700 because he was charged more than 40. Then we take the $8.10 and divide 0.45 into it. This then gives you 18 more minutes. Then add 18 to 700 and you get 718 min.
