a simple system with an impossible answer...

Jun 2019
^ That was my initial question, skipjack. The "and" made it sound that way, which seemed like it made it an indeterminate system.


Forum Staff
Dec 2006
If they can work together, but not on the same problems, jill should work for 3/2 hours to complete 6 chemistry problems, but stop doing the math problems after 9/7 hours, having complete 9 maths problems.

After 4/3 hours of working together, jack has completed 8 math problems and should stop doing math problems, but continue doing chemistry problems for a further 1/3 hours, completing 5 chemistry problems in total.

In this way, their combined efforts have (optimally) resulted in the completion of 11 chemistry problems and 17 math problems, as required.