Copyright © University of Cambridge. All rights reserved.

Tony owes Tina 40p. Then Tina borrows 50p from Tony. Later Tony gives Tina 60p. Who has to pay what to whom to square things up?

If you liked this problem, here is an NRICH task which 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*

View the current weekly problem