The amount of water decreases pints in 12 weeks.
Solution:
The amount of water decreases in 7 weeks = pints
The amount of water decreases each week is same.
Let us first change the mixed fraction into improper fraction.
pints =
pints
The amount of water decreases in 1 week
So, the amount of water decreases in 1 week is pints.
The amount of water decreases in 12 week
pints
Hence the amount of water decreases pints in 12 weeks.