Explanation:
Given that,
Mass of the lunchbox is 1800 grams or 1.8 kg
Let the box is in the shape of cube of side 20 cm. Its volume is : 20³ cm³
Density = mass/volume
So,
[tex]d=\dfrac{1800\ g}{(20)^3\ cm^3}\\\\d=0.225\ g/cm^3[/tex]
So, the density of the lunchbox is [tex]0.225\ g/cm^3[/tex].