Answer:
15 hours
Step-by-step explanation:
When reading the context it gives you two important numbers; the first one being (35).
Next important number is that she is going to spend (1) hour for each additional page she writes.
Third important number is that she needs a total of (50) pages.
Now lets arrange the numbers in an order we can find the solution to the problem at hand.
take 50-35=15. For her to have a total of 50 pages Jenna will need to write 15 more pages, if Jenna writes 15 more pages and each page takes an hour she will spend 15 hours total.