



 
Hi Sara, When the stone is placed in the water it displaces some of the water. If the stone doesn't absorb any of the water then the displaced water has a volume equal to the volume of the stone. The displaced water causes the water level to rise, in your case it rises 11  8 = 3 cm. Hence the volume of the stone is equal to the volume of the displaced water which is a slab of water 30 cm by 20 cm by 3 cm. I hope this helps,  


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