2020 AMC 8 Problems/Problem 11
After school, Maya and Naomi headed to the beach, miles away. Maya decided to bike while Naomi took a bus. The graph below shows their journeys, indicating the time and distance traveled. What was the difference, in miles per hour, between Naomi's and Maya's average speeds?
We use the formula . Naomi's distance is miles, and her time is minutes, which is equivalent to of an hour. Since speed is distance over time, Naomi's speed is mph. Using the same process, Maya's speed is mph. Subtracting those, we get an answer of .