In 2015, there were about 22 million teenagers (aged 13-17) in the United States. They each sent an average of 900 text messages per month. About how many text messages dial all of the teenager in the United States send each month? A 3.1 x 10^6
B. 2x 10^10
C.3.1 x 10^10
D. 2 x 10 ^6

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