Final answer:
Trista has 1/12 yard of ribbon remaining.
Step-by-step explanation:
To find the amount of ribbon remaining, we need to subtract the amount used from the total amount Trista has.
Trista has 3 3/4 yards of ribbon, and the first pillow used 2 1/6 yards, so we need to subtract 2 1/6 from 3 3/4. To subtract fractions, we need a common denominator.
The common denominator of 4 and 6 is 12, so we rewrite both fractions with a denominator of 12. 3 3/4 is equivalent to 9/4, and 2 1/6 is equivalent to 13/6.
Now we can subtract: 9/4 - 13/6 = 27/12 - 26/12 = 1/12.
Therefore, Trista has 1/12 yard of ribbon remaining.