I tried plugging in a smart number for work (12) which screws up the answer.Working independently x takes 12 hours to finish a certain work. He finishes 2/3 of the work. The rest of the work is finished by Y whose rate is 1/10 of X. In how much time does Y finish his work?
Why is plugging in a number for work not applicable here?
Can I ever plugin numbers in rate/work problems?