A tree initially measured 27 1/2 feet tall. Over the next 3 1/2 years, it grew to a final height of 35 1/2 feet. During those 3 1/2 years, what was the average yearly growth rate of the height of the tree? A. 2 1/7 feet/year
B. 2 2/7 feet/year
C. 2 4/7 feet/year
D. 2 6/7 feet/year

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm

Figure it out your self

She will need 5/8 bags for each square yard.