Four blocks with volume 1 m³ are dropped into identical vats of water. The blocks have different masses.

1. In which ones, if any, do the blocks float?
a) A only   b) D only   c) A,B   d) C,D   e) A,B,C

2. In which vat does the water level change the most? The least?

3. Could you devise a way to determine the mass of a block based on the change in water level?