Adisplay number cube measures 20 inches on a side. the sides are numbered 1-6. the odd numbered sides are covered in blue fabric and the even numbered sides are covered in red fabric. how much red fabric was used?

There are six sides or faces of a cube, each measuring 20 inches. If even numbered sides are covered with red fabric, then a total of 60 inches of red fabric was used. This is based from 3 even numbered sides multiplied to 20 inches as a measurement of each side. 

It simplify to 5/8 because 10/2=5 and 16/2= 8. Whatever you do to the numerator, you must do to the denominator.