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 $$2\over 3$$ 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?