1. **State the problem:** We need to find the volume of an L-shaped prism composed of two rectangular blocks. 2. **Identify dimensions:** - Lower block: width = 4 cm, depth = 5 cm, height = 15 cm - 8 cm = 7 cm - Upper block: width = 6 cm, depth = 5 cm, height = 8 cm 3. **Formula for volume of a rectangular prism:** $$\text{Volume} = \text{width} \times \text{depth} \times \text{height}$$ 4. **Calculate volume of lower block:** $$V_1 = 4 \times 5 \times 7 = 140 \text{ cm}^3$$ 5. **Calculate volume of upper block:** $$V_2 = 6 \times 5 \times 8 = 240 \text{ cm}^3$$ 6. **Calculate total volume:** $$V = V_1 + V_2 = 140 + 240 = 380 \text{ cm}^3$$ 7. **Answer:** The volume of the prism is **380 cm³**.