Answer:
9 yards of each quilt.
Explanation:
Let the length of each quilt be 'x'.
Given:
Length of green felt = 15 yards
Length of blue felt = 12 yards
Total number of quilts = 3
Total length of all the quilts in terms of 'x' is given as:
Total length is also equal to the sum of the lengths of green and blue felts. So,
Now, equating equations (1) and (2), we get:

Therefore, the length of each quilt is 9 yards.