The correct answer is 2.70 × 10² g or 270 g.
It is given, that the density of a metal is 9.80 g/ml.
Let the mass of a sample of metal be x.
The sample of metal is dropped in 28.9 ml of water, due to which the volume of the water increases to 56.4 ml.
In order to calculate the mass of a metal, there is a need to use the formula, mass = density * volume
Mass = (9.80 g/ml) (56.4 ml - 28.9 ml)
= (9.80 g/ml) (27.5 ml)
= 2.70 × 10² g or 270 g