Problem of the Week (Nov 15, 2021)
Three boys, Arthur, James, and Zain, are working on a set of math problems, each of equal difficulty. Together, they can solve one problem in 10 minutes. Arthur and James can solve two problems in 30 minutes. James and Zain can solve five problems in 1 hour and 40 minutes. How long does it take James to solve one problem by himself?
Source: The Editors
Happy problem solving!