Final answer:
The volume of the rock is 3 ml, calculated by the water displacement method which measures the change in water level in a graduated cylinder before and after the rock is submerged.
Step-by-step explanation:
To determine the volume of the rock, we use the displacement method, where the initial volume of water in the graduated cylinder is noted, and then the volume is noted again after submerging the rock. The volume of the rock is the difference between these two measurements. Initially, the water level was at 10 ml, and after placing the rock in the cylinder, the water rose to 13 ml. Therefore, the volume of the rock is 13 ml - 10 ml, which equals 3 ml.