A 25 kg rock is placed in a graduated cylinder with water. The volume of the fluid is 18.3ml calculate the density of the rock in g/ml

Are need you to please help me answer the question.

You don't have enough information.

density = mass rock/volume of rock.
If you mean the volume of the rock is 18.3 mL then
density = 25,000 g/18.3 cc = 1,366 g/cc but I don't believe that at all.
Usually one measures the volume of water in the graduated cylnder, adds the rock, reads the volume again and the volume of the rock is the difference between the two readings. You may have made a typo with the units. Repost if you find your error.