The volume of a cuboidal box is 48 cm

Suppose that the breadth of the box is $b \mathrm{~cm}$.

Volume of the cuboidal box $=48 \mathrm{~cm}^{3}$

Height of the box $=3 \mathrm{~cm}$

Length of the box $=4 \mathrm{~cm}$

Now, volume of box $=$ length $\times$ breadth $\times$ height

$\Rightarrow 48=4 \times b \times 3$

$\Rightarrow 48=12 \times b$

$\Rightarrow b=\frac{48}{12}=4 \mathrm{~cm}$

$\therefore$ The breadth of the cuboidal box is $4 \mathrm{~cm}$.