Question

What is the answer for number 11. Please

Answer 1

#11
Each roll is 9' long, 
length of each roll = 9' * (12"/foot) = 108"
Each ribbon piece = 15", so number of ribbons per roll
=108/15=7 with 3" left over, which is assumed not possible to be joined with other pieces.
Therefore, with 5 rolls, there are 7*5=35 pieces of ribbon, with 5 pieces or 3" left over.