ABC is an equilateral triangle with side 12 cm and AD is the median. Find the length of GD if G is the centroid of ΔАВС.

The base of a right pyramid is an equilateral triangle with side 8 cm, and its height is 30 √3 cm. The volume (in cm3) of the pyramid is:

A metallic solid spherical ball of radius 3 cm is melted and recast into three spherical balls. The radii of two of these balls are 2 cm and 1.5 cm. What is the surface area (in cm²) of the third ball?

A cylindrical roller made of iron is 1.2 m long. Its internal radius is 24 cm and thickness of the iron sheet used in making the roller is 15 cm. What is the mass (in kg) of the roller, if 1 cm³ of iron has 8 g mass?

A hemispherical tank full of water is emptied by a pipe at the rate of 7.7 litres per second. How much time (in hours) will it take to empty part of the tank, if the internal radius of the tank is 10.5 m?

The radius and height of a right circular cone are in the ratio 3: 4. If its curved surface area (in cm²) is 240 π, then its volume (in cm³) is:

The circumference of the base of a right circular cone is 44 cm and its height is 24 cm. The curved surface area (in cm²) of the cone is: (Taken π=22/7)

The sum of the radii of spheres A and B is 14 cm, the radius of A being larger than that of B. The difference between their surface areas is 112 π . What is the ratio of the volumes of A and B?