A graduated cylinder has a mass of 50 g when empty. when 30 mL of water is added, the graduated cylinder has a mass of 120 g. if a rock is added to the grand cylinder, the water level rises to 75 mL and the total mass is now 250 g. what is the density of the rock?

The answer to your question is:

a) The gold cube is larger.

b) lenght = 1.67 cm

Explanation:

Data

Platinum    density  21.45 g/cm3          100 gram cube

Gold           density  19.3 g/cm3            100 gram cube

Formula

           density = mass / volume

a) Calculate volume

           volume = mass / density

Platinum    volume = 100 / 21.45 = 4.66 cm3

Gold           volume = 100 / 19.3 = 5.18 cm3

b)  Volume = lenght³

   4.66 cm³ = lenght³

   lenght = ∛4.66

   lenght = 1.67 cm

i think it is northeast