Mrs. Peterson is going to install new baseboard in her living room,family room, and dining room. The total length of baseboard needed is 60 yards. If Mrs. Peterson buys 2 2/3 yard long baseboards, how peices will she need? If she buys 3 1/3 baseboards, how many peices will she need?
If Mrs. Peterson buys baseboards that are 2 2/3 yards long, she will need 60 / (2 2/3) yards = 60 / (8/3) yards = <<60/(8/3)=22.5>>22.5 pieces.
If Mrs. Peterson buys baseboards that are 3 1/3 yards long, she will need 60 / (3 1/3) yards = 60 / (10/3) yards = 18 pieces. Answer: \boxed{18}.