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.
