A body will float if its density is smaller than the density of water and will sink if its density is bigger than the density of water.
So, you need to calculate the density of the block.
Density = mass / volume
mass = 32 g
volumen = (3cm)^3 = 9 cm^3
=> density = 32 g / 9 cm^3 = 3.55 g/cm^3
Given that the density of water is 1.0 g /cm^3, the density of the block is greater and you conclude it will sink in water.
Answer: the block will sink in water