Answer
Volume of the closed rectangular box is $288$ cubic inches.
Surface area of the closed rectangular box is $280$ square inches.
Work Step by Step
The volume $V$ of a closed rectangular box is given by the formula $V=lwh$ where $l$ is its length, $w$ is its width, and $h$ is its height.
Substitute the given values.
$V=(9\text{ in.})(4\text{ in.})(8\text{ in.})$
$V=288 \text{ in.}^3$
Hence, the volume of the closed rectangular box is $288$ cubic inches.
The surface area $S$ of a closed rectangular box is given by the formula $S=2lh+2wh+2lw$ where $l$ is its length, $w$ is its width, and $h$ is its height.
Substitute the given values.
$S=2(9\text{ in.})(8\text{ in.})+2(4\text{ in.})(8\text{ in.})+2(9\text{ in.})(4\text{ in.})$
$S=144 \text{ in.}^2+64\text{ in.}^2+72\text{ in.}^2$
$S=280\text{ in.}^2$
Hence, the surface area of the closed rectangular box is $280$ square inches.
