A professional triathlete competes in an Austin bike race. She takes 1.5 hours to travel the entire course. Her speed varies from 0 kilometers per hour (km/hr), while stopped for a tire change, to 30 km/hr while riding downhill. The illustration shows her trip distances for each section of the race. What is the rider's average speed in km/hr during the 1.5 hour bike race?

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?