Step-by-step explanation:
this is confusing.
first the description says "the internal dimensions".
and then it tells us the thickness of the tank walls (1cm).
so, I am not sure what the given numbers describe.
in any case, the volume is length × width × height.
so, either
48×38×32
or
46×36×31 (as for length and width we need to consider 2 walls, one on each end, for the height only one wall, as the tank is open and lidless.
whatever you choose, make sure to mark the result as cm³.
