Hint: Since the average speed is the same, the ratio of distances is the same as the ratio of times. Indeed, let's say it took hours to drive from Blairtown to Ore City and hours to drive from Ore City to Janesville, and let the average speed be . Then the distance between Blairtown and Ore City is and the distance between Ore City and Janesville is . The ratio of these distances is is the same as the ratio of times.