Nice.
To make the slope we do y = mx + b
She starts from 0 and her rate is 10 pages per day.
y = 25x
Since we need to find when she does reach 325 pages, replace y with 325 as the number of days will multiply the number of pages per day and show us how many days take to reach 325.
325 = 25x
Simplify.
13 = x
It will take 13 days for her to reach the end of the book. She won't reach the end.