a).
-- There were 10.00 mL of water in the graduated cylinder originally.
-- After the marble was added to the cylinder and sank, the total volume
of water and marble in the cylinder was 11.20 mL.
-- The extra 1.20 mL that suddenly showed up was the volume of the marble.
-- We can use 1 mL = 1 cm³ .
-- The volume of the marble was 1.20 cm³ .
b).
Density = (mass) / (volume)
For the marble . . .
Density = (3.05 g) / (1.20 cm³) = 2.54 gm/cm³ (rounded)
