6th grade
let x be the juice (gallon) in 6th grade
6 water = 7 juice
24 water = x
cross-multiply
6x = 168
Divide both-side by 6
x= 28
Grade 6th is 28 juice (gallon
Grade 7th
Let y be the juice (gallon) in 7th grade
6 water = 7 juice
18 water = y
cross-multiply
6y =126
Divide both-side by 6
y = 21
In grade 7th , we have 21 juice (gallon)