Since the box is moving at a constant speed and in a rectilinear path, we can then say:
[tex]d = v \times t[/tex]
where d is the distance traveled.
where v is the speed.
& t is the time taken.
[tex]v= \frac{d}{t} = \frac{33}{1.5 \times 60} = \frac{33}{90} = 0.3666 \: meters \: per \: sec[/tex]
Don't forget to change from minutes to seconds by multiplying by 60.