You and your family take a trip to see your aunt who lives 100 miles away along a straight highway. The first 60 miles of the trip are driven at 55 mi/hmi/h but then you get stuck in a standstill traffic jam for 20 minutes. In order to make up time, you then proceed at 75 mi/hmi/h for the rest of the trip. What is the magnitude of your average velocity for the whole trip?Express your answer in miles per hour.

draw, graph and be step by step please