Question 804131
Full vessel, 40 kg.
Half-full vessel, 30 kg.
Amount of water for half full is 40-30=10 kg.


The amount of water is TWO halves so 10+10=20 kg. is the amount of water that the full vessel holds.


If v is weight of the vessel, and 20 is the weight of just the water, then 20+v=40.  Solving for v, find v=40-20,
v=20 kg.


The vessel is 20 kg.