Using the together rate, it is found that it would take the assistant 31 hours and 30 minutes to do it alone.
<h3>What is the together rate?</h3>It is the sum of each separate rate.
In this problem, the rates are given as follows:
- Josephine: 1/9.
- Assistant: 1/x.
- Together: 1/7.
Hence:
2x = 63
x = 31.5.
It would take the assistant 31 hours and 30 minutes to do it alone.
More can be learned about the together rate at brainly.com/question/25159431