Compare the density of the rubber to water. If it is less that 1 g/mL then it floats in the water.
You must compare density in the same units. So convert to g/mL
[tex]( \frac{495kg}{355L} )*( \frac{1000g}{1kg} )*( \frac{1L}{1000mL} ) = 1.39 g/mL[/tex]
The rubber does not float in water.
