The obvious way to answer the question is to record the odometer readings at the start and end of the trip and subtract them. But we suppose you neglected to do that, so you have to find the answer from the data in Figure 2. If you could find the average speed, you would only have to multiply that number by the elapsed time — `13` minutes — to get the distance. Conversely, if you can calculate the distance directly from the speed data, you can divide by the time to find the average speed. Thus finding distance and finding average speed are equivalent problems. If we can solve one, we can solve the other.