CBSE Class 9 Mental Maths Surface Area And Volume Worksheet

Question. An underground water tank is in the shape of cube of side 7 m. What will be its volume?
Answer : 343m³

Question. What will be volume of a box whose length 16 m, breadth 8 m and height is 5 m?
Answer : 640m³

Question. The length, breadth and height of a room are 12 m, 10 m, and 9m respectively. Find the area of four walls of room?
Answer : 396m²

Question. The volume of a cube is 27a³ . Find the length of its edge?
Answer : 3a

Question. How much Aluminium sheet will be required to make a container with lid whose length is 13 m, breadth is 8 m and height is 4 m?
Answer : 376m²

Question. The volume of a cube is 1331 cm3 . Find the length of its edge?
Answer : 11cm

Question. The length of diagonal of a cube is 17.32 cm. Find the volume of that cube?
Answer : 1000cm³

Question. Three cubes whose sides are 6 cm, 8 cm and 10 cm. They are melted and form a cube.
Find the volume of that cube?
Answer : 1728cm³

Question. Two cubes have edge 10 m. Their edges have been joined and form a cuboid. What will be the surface area of cuboid thus formed?
Answer : 1000m²

Question. The total volume of a cube is 512 cubic cm. Find the side of a cube?
Answer : 8cm

Question. A rectangular box 14 cm long, 10 cm wide and 5 cm high is to be made with card-board.
Find the area of card-board to make that box?
Answer : 520cm²

Question. What will be the volume of a cylindrical tank whose radius is 7 cm and height is 5 cm?
Answer : 770cm²

Question. How many solid spheres of 2/3 cm radius can be made from a solid sphere of 2 cm radius?
Answer : 27

Question. If the volume and surface area of a sphere is numerically same then what will be its radius?
Answer : 3 units

Question. The volume of a right circular cylinder is 392 π cm³ and its height is 8 cm. Find the radius?
Answer : 7cm

Question. The surface area of a sphere is 448 π cm² . Find its radius?
Answer : √112cm or 4√7cm

Question. What will be the edge of a cube? If its surface area is 324 sq cm .
Answer : 9cm

Question. The volume of a hemisphere is 144 π cm³. What will be its radius?
Answer : 6cm

Question. The curved surface area of a cone is 140 π cm². What will be the radius of cone whose slant height is 5 cm.
Answer : 28cm

Question. The radius of a solid sphere is 12 cm. How many sphere can be made from it of 6cm radius?
Answer : 8

Question. The volume of a cuboid is 840 cm³. If its length is 14 cm and breadth is 5 cm. Find the height of cuboid?
Answer : 12cm

Question. Four equal cubes have side 5 cm each. They are joined together edge to edge. What will be the surface area of cuboid thus formed?
Answer : 450cm²

Question. The area of a rhombus is 56 cm² and its diagonal is 7 cm. Find the length of other diagonal of the rhombus?
Answer : 16cm

Question. Find the maximum length of the rod that can be kept in cyboidal box of sides 30cm, 24cm and 18cm.
Answer : √1800cm or 30√2cm

Question. The curved surface area of a cylinder is 216 π . If its height is 18 cm then what will be its radius?
Answer : 6cm

Question. 60 circular plates of equal radius are placed on each other to form a cylinder. Find height of cylinder if thickness of each plate if 3/4 cm.
Answer : 45cm

Question. Curved surface area of a cone is thrice and curved surface area of the other. Slant height of second cone is thrice the slant height of first. Find ratio of their radii.
Answer : 9:1

Question. A well of 2m diameter is dug 14m deep on the ground. Find the volume of earth taken out.
Answer : 44m³

Question. Volume of a solid sphere is 36πcm³ . Find its radius.
Answer : 3cm

Question. A boy recasted a cone of 4cm height and 27cm radius into a solid sphere. Find the radius of the sphere.
Answer : 9cm