Answer:
342 inches, or 28.5 feet, or 9.5 yards
Explanation:
It is perhaps easiest to start with all the dimensions in inches.
13.5 ft = (13.5 ft)(12 in/ft) = 162 in
3.5 yd = (3.5 yd)(36 in/yd) = 126 in
Then the total of the lengths of ribbon is ...
54 in + 162 in + 126 in = 342 in
Converting to feet, we get ...
(342 in)/(12 in/ft) = 28.5 ft
And converting to yards, we get ...
(342 in)/(36 in/yd) = 9.5 yd
The total length of ribbon is 342 inches, or 28.5 feet, or 9.5 yards.