Answer:
8.99 hours
Step-by-step explanation:
Let represent the time needed for Jenny to do the job alone.
Let represent the proportion of time needed for Natalie to do the job alone.
Similarly, let represent the proportion of time needed for Jenny to do the job alone.
Therefore:
First, set the common denominator to :
Then, multiply both sides by :
Next, subtract from both sides:
Now, divide both sides by :
Therefore, it would take Jenny about 8.99 hours to do the job alone.