Emily needs 9 ribbons. she needs 5 that are each 15 inches long, 3 ribbons that are each 20 inches long, and 1 ribbon that is 28 inches long. ribbon is sold from a single roll and can be cut to the inch. emily needs to figure out how much ribbon to buy. she does not want to pay for any extra ribbon.

which statement is correct?

a.
emily must add all of the lengths together so she can buy exactly 163 inches of ribbon.

b.
it is okay to round each length of ribbon to the nearest foot, because it is easier to add the lengths.