Seriously?
Should we ignore the initial error that the dimensions are not a cube??? If not, then this is a trick question and the answer is zero because a cube of 2m x 3m x 4m does not exist in our universe.
Otherwise...
Google can tell you the density of Al: 2.70 gcm−3, and 1 m3 = 106 cm3
That gives a mass of 24 x 106 x 2.7 = 6.48 x108 g = 6.48 x105 kg
Assuming we are weighing it on the Earth, at standard 9.81ms-2
weight = 6.48x105 x 9.81 = 6.36x106 N
In other words, the answer is either very heavy or zero!