Answer : The mass of sample is 7.5 kilograms
Explanation :
Density : It is defined as the mass contained per unit volume.
Formula used :

Given :
Density = 3.00 g/mL
Volume = 2.50 L = 2500 mL
conversion used : (1 L = 1000 mL)
Now put all the given values in the above formula, we get:


conversion used : (1 kg = 1000 g)
Therefore, the mass of sample is 7.5 kilograms