---

Waiting for your answers...

Answer the following work problem. Report your answer to the nearest tenth of a day.

Petra can do a certain job in 10 days. Juan can do the same job in 9 days. Petra and Juan work together to complete the same job. However, Petra starts working 4 days after Juan starts to work. How many days will it take for them to complete the job once Juan starts to work? days