problem of the week math 7 about wallpaper borders

Question

Abbie is going to brighten up her room by adding wallpaper borders at the floor and ceiling of her walls.  The self-adhesive border paper she has chosen sells for $17.24 a roll, and each roll is 5 yards in lenght.  The norh and south walls of Abbies room are 3 3/4 yards long. the entrance to her room is in the south wall, and is 1 yard wide.  The east and west walls of Abbie's room are 4 1/2 yards long.  Her closet which is 2 1/8 yards wide, is located in the east wal.  How much will abbie spend remodeling?

Answer 1

The perimeter of the room is 2(3.75+4.5)=16.5 yds.

Assuming that the ceiling cover is unbroken all around the room, Abbie needs 16.5 yds to wallpaper the ceiling border. The total width of the closet and entrance is 2.125+1=3.125yd, so she only needs 16.5-3.125=13.375 yds of wallpaper for the floor border, total 16.5+13.375=29.875 yds.

One roll of wallpaper covers 5 yds, so she would need almost 30 yds=6 rolls @ $17.24 a roll=6×17.24=$103.44, which is the total cost.