First, find the total length of the remaining fabric by substracting 13 1/2 from 25:

Since one feet equals 12 inches, multiply 11 1/2 by 12 to find the total length of the remaining fabric in inches:

Since each ribbon takes 3 inches, divide 138 over 3 to find the total amount of ribbons that can be made:

Therefore, Sammi is able to make 46 ribbons.