Answer:
We need 108 cubes to fill the rectangular prism
Explanation:
We are given the dimensions of a cube with an edge length of 1/3 inch.
A rectangular prism is to be filled out with those cubes. The dimensions of the prism are 3 inches x 1 inch x 1 1/3 inches.
The fraction 1 1/3 is expressed as:

We need to know how many cubes fit in each dimension. It can be found by dividing them by their edge length:



Now we multiply the number of cube per dimension:
9*3*4=108
We need 108 cubes to fill the rectangular prism