Copyright © University of Cambridge. All rights reserved.
I walk to the bike shop at 3 miles per hour and cycle back along the same route at 12 miles per hour. What is my average speed in miles per hour, for the time I am actually travelling on the route?
If you liked this problem, here is an NRICH task that challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.
View the archive of all weekly problems grouped by curriculum topic