If you look at the question, you see that it is asking you to take a whole (24 hours) and divide it into parts (3 days). This tells us that the problem will be a division problem.
You would set up the problem as 24/3 (24 hours / 3 days) and you get 8 hours per day.
The answer is that Jasmine will need to devote 8 hours per day to complete the project.