Answer:
Since the fabrics are sold in yards she needs to buy at least 10 yards of fabric to make one pillowcase. She'll have a left over of 0.66 yards.
Explanation:
In order to find how much fabric Eva will need we have to convert the value she uses to make a pillowcase to yard, so the fabric and the amount she uses are in the same unit and can be compared. In order to do that we need to divide by 3, because 1 yard contains 3 feet. We have:
Pillowcase in yard = 28/3 = 9.34 yards
Since the fabrics are sold in yards she needs to buy at least 10 yards of fabric to make one pillowcase. She'll have a left over of 0.66 yards.