Can the volume displacement method be used for calculating the volume of unsinkable solids? Please someone help me I don’t get the question

No, the volume displacement method can not be utilized for calculating the volume of unsinkable solids.

A technique that could be used to quantify the moisture's amount displaced whenever the item has been immersed, precisely the overall volume of such bodies as well as other strangely shaped structures, is considered as the Displacement method.Across all solid substances, the methodology of water displacement cannot be utilized to measure the quantity of that material. Numerous solids are floating in the freshwater or liquid because of this.

Learn more about the Volume displacement method here:

link

No, the object must completely submerge to determine displacement volume.

However doing some math the volume displaced by a floating object (like a block of wood), can be calculated.

See the link below for a good example illustration. Sorting out weight, density and volume displaced.

https://youtu.be/eQsmq3Hu9HA