1. **State the problem:** We need to find the volume of a rectangular prism made up of unit cubes arranged in a 5 by 4 by 3 configuration. 2. **Formula for volume of a rectangular prism:** $$\text{Volume} = \text{length} \times \text{width} \times \text{height}$$ 3. **Identify dimensions:** Length = 5 cubes, Width = 4 cubes, Height = 3 cubes. 4. **Calculate volume:** $$\text{Volume} = 5 \times 4 \times 3$$ 5. **Multiply step-by-step:** $$5 \times 4 = 20$$ $$20 \times 3 = 60$$ 6. **Interpretation:** Since each cube represents 1 cubic inch, the total volume is 60 cubic inches. **Final answer:** $$\boxed{60 \text{ cubic inches}}$$