Surface Areas and Volumes-Important Questions

1.   A brick measures 30 cm × 10 cm × How many bricks will be required for a wall 30 m long. 2 m high and thick?

2.   The surface area of a cube is Find its volume.

3.   A hemispherical tank is emptied by a pipe at the rate of 5 litres per minute. How long will it take to half empty the tank if it is metre in diameter:

4.   If the heights of two cylinders are in the ratio of 4 : 3 and their radii are in the ratio of 3 : 4 then what is the ratio of their volumes?

5.   If the radius of the base of a solid cone is 'r' and its slant height is 1 then what is its lateral surface area?

6.   What is the total surface area of a cone, whose radius and slant height = 31?

7.   If a right circular cone has radius 4 cm and slant height 5 cm then what is its volume?

8.   The radius of a hemisphere is r. What is its volume?

9.   If the radius of a sphere is 2 r, then what is its volume?

10.   If the radius of a sphere is doubled then what is the ratio of their volumes?