**Important class 9 maths questions for Chapter 13** Surface Areas and Volumes are given here for students who are preparing for their final exams. All these questions are prepared by our subject experts based on CBSE syllabus and relevant to NCERT book for 9th standard. Practising these questions will help students to score well in their exams.

Students can revise by accessing the important questions for Class IX Maths of all the chapters here at BYJU’S. Chapter 13 of Class 9 maths deals with various solid shapes such as cube, cuboid, cone, cylinder and sphere. In this chapter, students will learn how to find the surface area and volumes of all these solids and how we can apply these formulas in word problems based on the real-world scenarios.

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## Important Questions For Class 9 Surface Areas and VolumesÂ (Chapter 13)

Q.1:Â Hameed has built a cubical water tank with lid for his house, with each outer edge 1.5 m long. He gets the outer surface of the tank excluding the base, covered with square tiles of side 25 cm (see in the figure below). Find how much he would spend on the tiles if the cost of the tiles is Rs.360 per dozen.

Q.2:Â The paint in a certain container is sufficient to paint an area equal to 9.375 sq.m.Â How many bricks of dimensions 22.5 cm Ã— 10 cm Ã— 7.5 cm can be painted out of this container?

Q.3:Â The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of whitewashing the walls of the room and the ceiling at the rate ofÂ Rs.7.50 per sq.m.

Q.4:Â The curved surface area of a right circular cylinder of height 14 cm is 88 sq.cm.Â Find the diameter of the base of the cylinder.

Q.5:Â Curved surface area of a right circular cylinder is 4.4 sq.m.Â If the radius of the base of the cylinder is 0.7 m, find its height.

Q.6:Â In a hot water heating system, there is a cylindrical pipe of length 28 m and diameter 5 cm. Find the total radiating surface in the system.

Q.7:Â The height of a cone is 16 cm and its base radius is 12 cm. Find the curved surface area and the total surface area of the cone.Â (Take Ï€ = 3.14)

Q.8:Â Find the total surface area of a cone, if its slant height is 21 m and diameter of its base is 24 m.

Q.9:Â The slant height and base diameter of a conical tomb are 25 m and 14 m respectively. Find the cost of white-washing its curved surface at the rate of Rs.210 per 100 sq.m.

Q.10:Â The hollow sphere, in which the circus motorcyclist performs his stunts, has a diameter of 7 m. Find the area available to the motorcyclist for riding.

Q.11:Â The radius of a spherical balloon increases from 7 cm to 14 cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases.

Q.12:Â A river 3 m deep and 40 m wide is flowing at the rate of 2 km per hour. How much water will fall into the sea in a minute?

Q.13:Â A lead pencil consists of a cylinder of wood with a solid cylinder of graphite filled in the interior. The diameter of the pencil is 7 mm and the diameter of the graphite is 1 mm. If the length of the pencil is 14 cm, find the volume of the wood and that of the graphite.

Q.14:Â Meera has a piece of canvas whose area is 551 m^{2}. She uses it to have a conical tent made, with a base radius of 7 m. Assuming that all the stitching margins and the wastage incurred while cutting, amounts to approximately 1 m^{2}, find the volume of the tent that can be made with it.

Q.15:Â A capsule of medicine is in the shape of a sphere of diameter 3.5 mm. How much medicine (in mm^{3}) is needed to fill this capsule?