Joy started with 2.75 gallons of milk. She used 1.5 pints to make mashed potatoes and another cup to make cookies. How much milk does joy have left?

Unit conversions:

1 pint = 0.125 gallons

1 cup = 0.0625 gallons

Now,

Total volume of milk = 2.75 gallons

Milk used for mashed potato = 1.5 pints = 1.5*0.125 = 0.1875 gallons

Milk used for cookies = 1 cup = 1*0.0625 = 0.0625 gallons

Milk left = 2.75 - 0.1875 - 0.0625 = 2.5 gallons

Amount of cups Joy has=2.75

1 cup=0.0625 gallons

1 pint=0.125 gallons

amount used to make mashed potatoes:

1.5*0.125=0.1875 gallons

amount used to make cookies=0.0625 gallons

total amount of milk used:

0.0625+0.1875=0.25

Remaining amount

=2.75-0.25=2.5 gallons