Question

You can find the volume of an irregularly shaped solid object by completely submerging it in water and calculating the volume of water the object displaces. You completely submerge a solid object in a rectangular tank that has a base 40 centimeters by 30 centimeters and is filled with water to a depth of 20 centimeters. The object sinks to the bottom, and the water level goes up 0.25 centimeters. What is the volume, in cubic centimeters, of the object?

Answer 1

The volume of the object equals the volume of water the item is displaced.
That volume of that would be 40 cm by 30 cm by 0.25 cm = 300 cm^3

Answer 2

The amount of water is 40 x 30 x 20, which is 24,000. 
It goes up by 0.25, so add 0.25 to 20 and rework it. 
40 x 30 x 20.25 = 24,300 
That is 300 more than without the object. 
So, the object is 300 cm³ in volume. 
Hope this helps!