Adress needs 3 1/4 yards of fabric to make. if the matching jacket requires 5/6 less yards of fabric. how much fabric is needed for both pieces?

Fabric needs to make a dress = 3 1/4
fabric needs to make jacket= 3 1/4 - 5/6
= 29/12 or 2 5/12
Hence total fabric needed for both pieces is
= 3 1/4 + 2 5/12
= 68/12 or 5 8/12 or 5 2/3 yards