find the volume of the right rectangular prism packed with 12 cubes. each cube has an edge length of 1/2 inch.

3/2 cubic inches
12 cubic inches
1/8 cubic inches
5 cubic inches

The volume of each cube is (1/2)^3 = 1/8 cubic inches.

Since there are 12 cubes packed in the prism, the total volume is 12 * (1/8) = 1.5 cubic inches.

Therefore, the correct answer is 3/2 cubic inches.