Option D:
160 plastic cubes can fit into the box.
Solution:
Convert mixed fraction into improper fraction.
Length of the box = 4 ft
Width of the box = [tex]2\frac{1}{2}=\frac{5}{2}[/tex] ft
Height of the box = 2 ft
Volume of the box = length × width × height
[tex]$=4\times\frac{5}{2} \times2[/tex]
= 20 ft³
Volume of the box = 20 ft³
Length of the plastic cube = [tex]\frac{1}{2}[/tex] ft
Volume of the cube = length × length × length
[tex]$=\frac{1}{2} \times\frac{1}{2} \times\frac{1}{2}[/tex]
[tex]$=\frac{1}{8} \ \text{ft}^3[/tex]
Volume of the cube = 0.125 ft³
[tex]$\text{Number of plastic cubes}=\frac{\text{Volume of box}}{\text{Volume of cube}}[/tex]
[tex]$=\frac{20}{0.125}[/tex]
= 160
Number of plastic cubes = 160
Hence 160 plastic cubes can fit into the box.
Option D is the correct answer.