The length of canvas 1.1 m wide required to build a conical tent of height 14m and the floor area 346.5 $m^{2}$ is

One cubic metre of iron weighs 7.800 kg. The weight of iron in a pipe of length 4 m, whose interior and exterior diameters measure 10 cm and 12 cm respectively, is nearly

A pump can be operated both for filling a tank and for emptying it. The capacity of the tank is 2400 $m^{3}$. The emptying capacity of the pump is 10 $m^{3}$ per minute higher than its filling capacity. Consequently, the pump needs 8 minutes less to empty the tank as to fill it. The filling capacity of the pump is

A solid cone and a solid cylinder have equal base and equal height. If the radius and height be in the ratio of 12 : 5, the ratio of the total surface area of cone to that of the cylinder is

A 30 meter deep well, with a diameter of 7 meters is dug and the earth from digging is evenly spread out to form a platform of size 22 meters by 14 meters. The height of the platform is:

Consider the following statements, which of them is/are correct?

A. If the height of cylinder is doubled, the area of curved surface is doubled.

B. If the radius of a hemispherical solid is doubled, its total surface area becomes fourfold.

C. If a hemisphere and cone have equal bases and equal heights, then the ratio of curved surface area is $\sqrt{2}:1$.

An aluminum sheet 25 cm long, 20 cm broad and 2 cm thick is melted into a cube. The difference in the surface area of the two solids would be