After Brandon rent it for the first 4 hour, it cost 10$ per hour. 60$ (his money) subtracted by 30$ (he spent on first 4 hour) is 30$. This mean he only have 30$ to spent on remain hours. 30$รท10$ is 3, showing that he can rent it for 3 additional hours. 4 hours (from the 30$ for first 4 hour) plus 3 hours is 7 hours. The answer is 7 hours.