Isabella jarred 15 liters of jam after 5 days. How many days does Isabella need to spend making jam if she wants to jar 27 liters of jam in all? Assume the relationship is directly proportional.

Afitness center has 2 membership plans one has a low dollar sign up fee of 15 dollars and costs 38 dollars per month to join. a second plan has a higher sign up fee of 78 dollars but a lower monthly fee of 31 dollars for what number of days of the month is the coat the same