This is for my cousin and i really can't him.

Okay so all you have to do is find the probability that the top will land on the left side of the tape. the probilty is 28/40. now all you have to do is turn it into a percent. to turn a fraction into a percent you have to divide the numarater by the dimamanter and then multiply it by 100
so you would get 70%

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