Puzzlemaker Clip Art Gallery Lesson Plan Library Kathy Schrock's Guide for Educators Brain Boosters Learning Adventures Science Fair Central Curriculum Center On TV Young Scientist Challenge Enter Username Custom Classroom Resources will not be available after August 1st, 2008. If you would like to access resources you have created for future use, you will need to save them to your local computer.

Number & Math Play Average Speed   Louise runs the first half of a race at 5 miles per hour. Then she picks up her pace and runs the last half of the race at 10 miles per hour. What is her average speed on the course?   The answer is not 7.5 miles per hour. Assume the course is 20 miles long. Louise needs 2 hours to run the first 10 miles (the first half of the course) and 1 hour to run the last 10 miles (the last half), meaning she needs 3 hours to run the total of 20 miles. Therefore, her average speed is 6.7 (or 6 2/3) miles per hour. Source: Carter & Russell, Classic Brain Puzzlers, p.57

Check Requirements  |  Terms of Use  |  Privacy Policy  |  Contact Us

Copyright © 2008 Discovery Education. All rights reserved. Discovery Education is a Division of Discovery Communications, LLC.