Solution:
The cuboid is a solid-shaped figure formed by six faces. A cuboid is a simple figure. It has three dimensions - width, length, and height. Thus, the cuboid is a parallelepiped. Now, the surface area of the parallelepiped is the sum of the areas of all sides, that is:
![S\text{ =2(}lw+lh+wh\text{)}](https://img.qammunity.org/2023/formulas/mathematics/college/mclz2nrxl0lqxqodv27jchrlgthorfq6yx.png)
where
l is the lenght
w is the width
and
h is the height
According to the figure given in the problem, we have that:
l = 30
w = 10
h = 10
thus, the surface area of the given cuboid would be:
![\begin{gathered} S\text{ =2(}lw+lh+wh\text{)} \\ \text{ = 2((}30\cdot10\text{)+(30}\cdot10\text{)+(10}\cdot10\text{))=}1400 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/jqsnf027gqd6mt3tkd9louol3r60jbi6y5.png)
So that, we can conclude that the correct answer is:
![1400](https://img.qammunity.org/2023/formulas/mathematics/college/jikdwrwewbmhqihih8we9hygtpd12iocmo.png)