**Notes**
**Ncert Solutions**
**Assignments**
**Revision sheet**
Given below are the **Class 9 Maths** Assignments for Surface area and volume

a) Concepts questions

b) Calculation problems

c) Multiple choice questions

d) Long answer questions

e) Fill in the blank's

**Question 1)**Ramesh has build a cuboidal water tank with lid for his house with each outer edge 1.5m long. He gets the outer surface of tank excluding the base, covered with square tiles of side 25cm. Find how much he would spend for tiles, if cost of the tile is Rs 400 per dozen.

**Question 2)**The paint in a certain container is sufficient to point an area equal to 1.375m

^{2}. How many bricks of dimensions 22.5cm x 10cm x 7.5cm can be painted out of this container.

**Question 3)** Bikanerwala sweets shop was planning an order for making cardboard boxes for packing their sweets. Two sizes of boxes were required. The bigger of dimensions 25cm x 20cm x 5cm and smaller of dimensions 15cm x 12cm x 5cm. For all overlaps, 5% of total surface area is required extra. If cost of cardboard is Rs 4 for 1000cm

^{2}, find the cost of cardboard required for supplying 250 boxes of each kind.

**Question 4)** The dimensions of a roller are 84cm and its length is 120cm. It takes 500 complete revolutions to move once more over to level a playground. Find area of playground in m

^{2}?

**Question 5)**In a hot water heating system, there is a cylindrical pipe of length 28m and diameter 5cm. Find the total radiating surface in system?

**Question 6)** Find

a)the lateral or C.S.A of a closed cylindrical petrol storage tank that is 4.2m in diameter and 4.5m in high

b)how much steel was actually used, if 1/12 of steel actually used was wasted in making the tank.

**Question 7)** You see the frame of lamp shade. It is to be covered with decorative cloth. The frame has a base diameter of 20cm and height of 30cm. A margin of 2.5cm is total given for folding it over top and bottom of frame How much cloth is required for covering the lamp shade?

**Question 8)** What length of tarpaulin 3m wide will be required to make a conical tank of height 8m and base radius 6m. Assume that the extra length margins and wastage n cutting is approximately 20cm. (Use = 3.14)

**Question 9)** A Birthday cap is in form of right circular cone of radius 7cm and height 24cm. Find area of sheet required to make 10 such caps?

**Question 10)** A bus stop is barricaded from remaining part of road, by using 50 hollow cones made of recycles cardboard. Each cone has a base diameter of 4cm and height 1m. If outer side of earn cone is to be painted and cost of painting is Rs 12/m

^{2}. What will be the cost? ( = 3.14 and take 1.04 = 1.02)

**Question 11)** A hemispherical dome of a building needs to be painted. If circumference of base of dome is 17.6m, find the cost of painting it, given cost of painting is Rs. 5/200cm

^{2}.

**Question 12)** The diameter of moon is approximately one – fourth diameter of earth. Find the ratio of their surface areas. and What

fraction of the volume of the earth is the volume of the moon?

**Question 13)**A right circular cone just enclosed a sphere of radius r. Find –

a)surface area of sphere

b)curved surface area of cylinder

c)ratio of areas obtained in (i) and (ii)

**Question 14)** A wall of length 10m was to be built across an open ground. The height is 4m and thickness is 24cm. If this wall is to be build up with bricks whose dimensions are 24cm x 12cm x 8cm, how many bricks would be required?

**Question 15)** Three cubes of each side 4cm are joining end to end. Find the surface area of resulting cuboid

**Question 16)**A village having a population of 4000 requires 150 litres of water per head per day. It has a tank measuring 20m x 15m x 6m for how many days will the water of this tank last?

**Question 17)** A godown measures 40m x 25m x 10m. Find the maximum no. of wooden crates each measuring 1.5m x 1.25m x 0.5m that can be stored in godown?

**Question 18)** A river 3m deep and 40m wide is flowing at the rate of 2km/hr. How much water will fall into the sea in a minute?

**Question 19)** The pillars of a temple are cylindrically shaped. If each pillar has a circular base of radius 20cm and height 10m. How much concrete mixture would be required to build 14 such pillars?

**Question 20)** At ramzan Mela, a stall keeper in one of the food stalls has a large cylindrical vessel of base radius 15cm filled up to a height of 32cm with orange juice. The juice is filled in small cylindrical glasses of radius 3cm up to a height of 8cm and sold for Rs 3 each. How much money does the stall keeper receive by selling the juice completely?

**Question 21)** 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 7mm and diameter of graphite is 1mm. If the length of the pencil is 14cm, find the volume of wood and that of graphite.

**Question 22)**A right triangle ABC with sides 5cm, 12cm and 13cm is revolved about the side 12cm. Find the volume of the solid so obtained?

**Question 23)** A heap of wheat is in the form of a cone whose diameter is 10.5m and height is 3m. Find its volume. The heap is to be covered by canvas to protect it from rain. Find the area of the canvas required?

**Question 24)** A shot- putt is a metallic sphere of radius 4.9cm. If the density of the metal is 7.8g/cm

^{3}, find the mass of shot- putt?

**Question 25)** A hemispherical tank is made up of iron sheet 1cm thick. If the inner radius is 1m, then find the volume of iron used in making the tank.

**Question 26)** A dome of the building is in form of a hemisphere from inside, it was white – washed at the cost of Rs 498.96. If the cost of white- washing is Rs. 2.00/sq.m find the

a)inside surface area of dome

b) volume of air inside dome

**Question 27)** Twenty seven solid spheres, each of radius ’r’ and surface area ‘s’ are melted to form a sphere with surface area ‘s’. Find the –

a)radius ‘r’ of new sphere

b)ratio of s and ‘s’

**Question 28)** The sum of length, breadth and height of a cuboid is 21 cm and the length of its diagonal is 12 cm. Find the surface area of the cuboid.

**Question 29)** The dimensions of a cubiod are in the ratio of 1 : 2 : 3 and its total surface area is 88sq m. Find the dimensions. Ans: 2, 4, 6 cm

**Question 30)** Find the volume of the largest right circular cone that can be fitted in a cube whose edge is 14cm.

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Class 9 Maths
Class 9 Science