guy plzz help me the this and thanks

Answer:
Explanation:
In first picture,
When rock was not in the cylinder,
Volume of water
[tex] = {18cm}^{3} [/tex]
In second picture,
When rock is in the cylinder,
Volume of water
[tex] = {36cm}^{3} [/tex]
Hence,
Volume of rock
[tex] = 36 {cm}^{3} - {18cm}^{3} [/tex]
[tex] = 18 {cm}^{3} (ans)[/tex]