I am not sure what kind of equation you want, but you could possibly use something like _ x 3 = 15
Answer: 
Step-by-step explanation:
Given
Rami practices his saxophone for 
hour on 4 day each week
So, for a week she practices around
Converting it into mixed fraction
Length in feet multiplied by width in feet multiplied by height in feet divided by 27 equals cubic yards needed.
When dealing in inches: convert inches to feet by dividing by 12.
For example: pour a 25 ft. sidewalk 5 ft. wide and four inches deep.
(25’ x 5 ‘ x 0.333’) / 27 = 1.54 cubic yards
Note* we achieved 0.333 ft. by taking four inches and dividing by twelve.
Another example: yardage for an 80 ft. driveway, 24 ft. wide and 5 inches deep.
(80’ x 24’ x 0.416’) / 27 = 29.58 cubic yards
