Answer:
Step-by-step explanation:
According to the problem, the ratio between water and juice is the same for all three grades, this means that each increase on each element is the same at every grade.
We know that 5th grade consumed 4 gallons of water and 9 gallons o juice. This ration is represented as
[tex]4:9[/tex]
Then, 6th grade consumed 20 gallons of water, that is, 5 times more the water consumed by the 5th grade. So, if they are in the same ratio, then the consumption of juice by the 6th grade is also five times. So, the ratio for 6th grade would be
[tex]20:45[/tex]
We apply the same logical process for 7th grade. Due to the same ratio, they also consumed five times more water and juice. So, the ratio of the 7th grade is
[tex]100:225[/tex]
5th grade [tex]4:9[/tex]
6th grade [tex]20:45[/tex]
7th grade [tex]100:225[/tex]