A solid cube just gets completely immersed in water when a 0.2 kg mass is placed on it. If the mass is removed, the cube is 2 cm above the water level. What is the length of each side of the cube ?

Answer: Option C

Let the length of each side of the cube be a cm
Then, Volume of the part of cube outside water = Volume of the mass placed on it
⇒ 2a² = 0.2 × 1000
⇒ 2a² = 200
⇒ a² = 100
⇒ a = 10