A solid has a uniform cross-section and a length of 30 cm. If its volume is 1200 cm³, what is the area of its cross-section?

The volume of a prism (a solid with a uniform cross-section) is given by the formula:

$$V = A \times L$$

where $V$ is the volume, $A$ is the area of the cross-section, and $L$ is the length of the solid.

Given:
Volume ($V$) $= 1200 \text{ cm}^3$
Length ($L$) $= 30 \text{ cm}$

$$A = \frac{1200 \text{ cm}^3}{30 \text{ cm}}$$ $$A = 40 \text{ cm}^2$$

The area of the cross-section is $\text{40 cm}^2$.