
Step-by-step explanation
A box is a rectangular prism, the volume for this shape is given by:

so
Step 1
as we need the answer is cubic meters,we need to convert the measures ( given in cm) into meteres, so
the equivalence is

to convert each measure, multiply the measure by the fraction,
a)100 cm

b)20 cm

c) length:0.5 m
as the heigth is given in meters,we don´t need to convert ,

Step 2
now, replace in the formula to find the volume

so, the answer is

I hope this helps you