In the following question, two statements are numbered as A and B. On solving these statements, we get quantities A and B respectively. Solve both quantities and choose the correct option.

Quantity I: The perimeter of an Equilateral triangle is 30cm. The unequal side of an isosceles triangle is half of the side of an Equilateral triangle. The perimeter of an isosceles triangle is 29cm. The equal side of an isosceles triangle is equal to the side of the cube. Find the volume of the cube.

Quantity II: A Cuboidal box of certain thickness having dimensions of 12cm × 20 cm × 20cmis filled with 1 cubic.cm cubes. If there are 3240 cubes kept inside the box, then the difference between the external and internal volume of the cuboid  is –