Number 1 is hypo tonic because solute is going into the cell. The cell is getting bigger and expanding. You can think of Hypotonic as getting bigger by using Hypo which can be Hippo. Hippos grow bigger over time.
Number 2 is Isotonic. The water is going in and out at the same rate. Therefore, nothing really changes here.
Number 3 is Hypertonic because the cell has shrunk.
