Working together, Sarah and Jeff can do a task in 6 hours. Jeff uses a motorized cart to do the task, whereas Sarah uses a pushcart. If each person does the task without the help of the other, it takes Sarah twice as long as it takes Jeff. How long does it take Sarah to complete the task?

Question

Working​ together, Sarah and Jeff can do a task in 6 hours. Jeff uses a motorized cart to do the​ task, whereas Sarah uses a pushcart. If each person does the task without the help of the​ other, it takes Sarah twice as long as it takes Jeff. How long does it take Sarah to complete the​ task?

Reiny · Answer

see http://www.jiskha.com/display.cgi?id=1487716112 this is very similar, except you would have 1/x and 1/2x as the combined rate, and you know that result.