Xavier bought 3 quarts of milk for his family. they drank 1-quarts for
breakfast and quart for snacks.
which procedure can be used to
determine the amount of milk that is
left?

The answer is B. Once you combine the two amounts consumed (which you’d put them in like terms and reduce) you’d subtract the sum from 3

There for
1 1/4 = 1 2/8
1 2/8+7/8 = 1 9/8
1 9/8 = 2 1/8

2 1/8 is the sum of the amount consumed there for,
3- 2 1/8 = 7/8

If you solved with A you would essentially be adding a initial quart of 3 and 1 1 1/4 which assumes you added milk then drank 7/8 of a quart, C assumes you don’t consume any and you have 1 1/4 and 7/8 quarts of milk above the 3 quarts and D would leave you with 1.125 or 1 1/8 there for it is also incorrect.