From 10 rolls of 6-feet-long ribbon, the dressmaker can cut a total of 40 pieces of 18 inches each.
Calculating the total length of ribbon:
Each roll of ribbon is 6 feet in length. Since there are 10 rolls:
Total length of ribbon in inches = (Length of one roll in feet * 12 inches per foot) * Number of rolls
Total length of ribbon = (6 feet * 12 inches/foot) * 10 rolls
Total length of ribbon = 72 inches/roll * 10 rolls
Total length of ribbon = 720 inches
So, the dressmaker has a total of 720 inches of ribbon in 10 rolls.
Calculating the number of 18-inch pieces the dressmaker can cut:
The dressmaker needs to cut 18-inch pieces from this total length.
Number of 18-inch pieces = Total length of ribbon / Length of each 18-inch piece
Number of 18-inch pieces = 720 inches / 18 inches
Number of 18-inch pieces = 40
Therefore, from 10 rolls of 6-feet-long ribbon, the dressmaker can cut a total of 40 pieces of 18 inches each.