5/6 of an hour is 50 minutes. 50 (time) divided by 8 (tasks) is 6.25. So, it takes the robot 6 minutes and 15 seconds (.25 of a minute is 15 seconds) to complete one task. Now, just divide 60 by 6.25. It's 9.6. Since a robot cannot complete .6 of a task, the robot only completes 9 tasks in an hour.
