help me please the last question

Answer:
17/7, y = 21 * (17/7), 51
Step-by-step explanation:
so to find what x is, we need to find how much it rises in 1 minute. we do that by dividing 17 by 7. we then see that we want to find how much is it filled in 21 minutes. we then multiply (17/7) by 21 to find the y which is 51