Answer:
49 liters
Explanation:
We know that Christina jarred 21 liters of jam in 3 days, so using this ratio, we can calculate the how much jam she jarred after 7 days as follows
[tex]7\text{ days}\times\frac{21\text{ liters}}{\text{ 3 days}}=49\text{ liters}[/tex]Therefore, the answer is 49 liters.
