it will end at 12:30 because if every class is 1 hour, you multiply 1 times 4 to get 4. 8:00 am plus four hours gets you at 12:00 pm. then you add the transition time. since you transition 3 times from first to second, second to third, and third to fourth, you multiply 3 times 10(time of each transition) to get 30. add 30 minutes to 12:00 and the class ends at 12:30.
