to find the number of hours it will take to travel 82.5 kilometers through the ice. FUNDRAISING A school is raising money by selling calendars for $20 each. Mrs. Hawkins promised a party to whichever of her English classes sold the most calendars over the course of four weeks. Use the table to answer Exercises 18-20. 18. Write and solve an equation to show the average number of calendars her 3rd period class sold per week during the four-week challenge. Mrs. Hawkins' Fundraising Challenge Number of Class Calendars Sold 1st Period 60 123 2nd Period 3rd Period 89 4th Period 126 Copy the crew Companies, Inc. Permission is granted to reproduce for classroom use. 19. How many calendars did the 1st and 2nd period classes sell on average per week? Write and solve a multiplication equation. 20. What was the average number of calendars sold in a week by all of her classes?