Final answer:
The environment is hypotonic to the cell, as its solute concentration is lower, causing water to move into the cell and potentially leading to the cell swelling.
Step-by-step explanation:
If a cell with a 30% solute concentration is in an environment with a 25% solute concentration, the environment is hypotonic to the cell. In a hypotonic solution, the solute concentration outside the cell is lower than inside the cell, leading to a net influx of water into the cell. This can cause the cell to swell and potentially lyse if the influx is too great. On the contrary, in a hypertonic solution, the solute concentration outside the cell is higher, causing water to move out of the cell, which may lead to cell shrinkage. Lastly, an isotonic environment has an equal solute concentration to that within the cell, resulting in no net movement of water across the cell membrane.