If the area of the base, height and volume of a right prism be  and 7200 cm³ respectively, then the value of P will be

A circular swimming pool is surrounded by a concrete wall 4m wide. If the area of the concrete wall surrounding the pool is  that of the pool, then the radius (in m) of the pool is

• 20

• 30

• 16

• 16

13.

A conical iron piece having diameter 28 cm and height 30cm is totally immersed into the water of a cylindrical vessel, resulting in the rise of water level by 6.4 cm. The diameter (in cm) of the vessel is

• 3.5 

• 

• 35

• 35

The area of the iron sheet required to prepare a cone 24 cm high with base radius 7 cm is .

• 708 cm²

• 804 cm²

• 704 cm²

• 704 cm²

A rectangular tin sheet is 12 cm long and 5 cm broad. It is rolled along its length to form a cylinder by making the opposite edges just to touch each other. Then, the volume of the cylinder is

• 180/π cm³

• 120/π cm³

• 100/π cm³

• 60/π cm³

The radius of a sphere and hemisphere are same. The ratio of their total surface areas is

• 3 : 1

• 2 : 1

• 3 : 2

• 3 : 2

The height of a right circular cylinder is twice its radius of the base. If its height be 6 times its radius of the base, then the volume of the cylinder will be 539 cm³ more. Assuming  the height of the cylinder is

• 5 cm

• 7 cm

• 9 cm

• 9 cm

A sphere of radius 5 cm is melted to form a cone with base of same radius. The height (in cm) of the cone is

• 5

• 10

• 20

• 20

The volume of metallic cylindrical pipe of uniform thickness is 748 cm³. Its length is 14 cm and its external radius is 9 cm. The thickness of the pipe is

• 0.5 cm

• 1.5 cm

• 1 cm

• 1 cm

If the sum of radius and height of a solid cylinder is 20 cm and its total surface area is 880 cm² then its volume is

• 1760 cm³

• 8800 cm³

• 2002 cm³

• 2002 cm³