1. **State the problem:** We need to find the volume of a prism whose cross-section is composed of two rectangles stacked vertically. 2. **Identify the dimensions:** The bottom rectangle has dimensions 3 cm by 5 cm. The top rectangle has dimensions 7 cm by 6 cm. The total height (length) of the prism is 15 cm. 3. **Formula for volume of a prism:** $$\text{Volume} = \text{Area of cross-section} \times \text{length}$$ 4. **Calculate the area of each rectangle:** - Bottom rectangle area: $$3 \times 5 = 15 \text{ cm}^2$$ - Top rectangle area: $$7 \times 6 = 42 \text{ cm}^2$$ 5. **Calculate total cross-sectional area:** $$15 + 42 = 57 \text{ cm}^2$$ 6. **Calculate the volume:** $$\text{Volume} = 57 \times 15 = 855 \text{ cm}^3$$ 7. **Answer:** The volume of the prism is $$855 \text{ cm}^3$$.