A classroom has a volume of 288m3.

What is its volume in km3

The conversion factor between the unit in meter and that of kilometer is that, 1 kilometer = 1000m

For the given above,

(288 m³) x (1 km / 1000 m) ³ = 2.88 x 10^-7

Thus, 288 m³ is also equal to 2.88 x 10^-7 km³.