hi friends,
this is the solution of my ice riddle.
this new riddle is the opposite of the first one: it seems a problem of volume but is a problem of weight. the most important thing here is that the ice and the water are the same chemicals, the first in a solid state and the second in a liquid state.
because the ice displaces a volume of water equal to its own weight (principle of archimedes again) and because its weight remains the same when it melts then, when the ice melts, the water produced will fill exactly the volume displaced so the level of water will remain the same.
game over.