Question

A vessel full of water weights 16.5kg. When the vessel is half full, it weighs 10.5 kg. Find the weight of the empty vessel

Answer 1

Let the weight of empty vessel be x.
Therefore, Weight of full water = 16.5 - x.
When water is half full,
$x + \frac{16.5 - x}{2} = 10.5 \\ x = 4.5$