Fair Share

Trina and Mariel were paid $60 to paint the garage. Mariel started at 8 AM and Trina did not arrive until 10 AM. The work was completed at 2 PM. What is Mariel’s fair share of the earnings?

Extension
Describe her fair share if the work was completed at x o’clock pm.

(Source: Adapted from Mathematics Teaching in the Middle School, May 1998)