Question 1 :
A cone is 8.4 cm high and the radius of its base is 2.1 cm. It is melted and recasted into a sphere. Find the radius of the sphere.

Question 2 :
30 circular plates, each of radius 14 cm and thickness 3cm are placed one above the another to form a cylindrical solid. Find volume of the cylinder so formed.

Question 3 :
State true or false : Cuboid whose length = l, breadth = b and height = h ; Volume of cuboid = lbh

Question 4 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d23af59b460d7261f56d.jpeg' /> In the above image, a metal pipe is 77 cm long. The inner diameter of a cross section is 4 cm, the outer diameter being 4.4 cm. Find its outer curved surface area.Assume $\pi$ =$\frac{22}{7}$.

Question 5 :
The volume of a right circular cone is 9856 $cm^3$ . If the diameter of the base is 28 cm, find the curved surface area of the cone.

Question 6 :
State true or false. An edge of a cube measures r cm. If the largest possible right circular cone is cut out of this cube, then the volume of the cone (in $cm^3$) is $(\frac{1}{6})\pi r^3$.

Question 7 :
A cylindrical pillar is 50 cm in diameter and 3.5 m in height. Find the cost of painting the curved surface of the pillar at the rate of Rs 12.50 per $m^2$.Assume $\pi$ =$\frac{22}{7}$.

Question 8 :
Find the volume of a sphere whose surface area is 154 $cm^2$ .

Question 10 :
A soft drink is available in two packs – (i) a tin can with a rectangular base of length 5 cm and width 4 cm, having a height of 15 cm and (ii) a plastic cylinder with circular base of diameter 7 cm and height 10 cm. Which container has greater capacity and by how much?

Question 11 :
Twenty seven solid iron spheres, each of radius r and surface area S are melted to form a sphere with surface area S′. Find the ratio of S and S′.

Question 12 :
The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs 7.50 per $m^2$ .

Question 13 :
A solid cube of side 12 cm is cut into eight cubes of equal volume. What will be the side of the new cube?

Question 14 :
A cuboidal water tank is 6 m long, 5 m wide and 4.5 m deep. How many litres of water can it hold? (1 $m^3$ = 1000 $l$)

Question 15 :
A hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of Rs 16 per 100 $cm^2$ .

Question 16 :
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?

Question 17 :
A semi-circular sheet of metal of diameter 28cm is bent to form an open conical cup. Find the capacity of the cup.

Question 18 :
The inner diameter of a cylindrical wooden pipe is 24 cm and its outer diameter is 28 cm. The length of the pipe is 35 cm. Find the mass of the pipe, if 1 $cm^3$ of wood has a mass of 0.6 g.

Question 19 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d234f59b460d7261f564.jpeg' /> In the above image, Mary wants to decorate her Christmas tree. She wants to place the tree on a wooden box covered with coloured paper with picture of Santa Claus on it. She must know the exact quantity of paper to buy for this purpose. If the box has length, breadth and height as 80 cm, 40 cm and 20 cm respectively how many square sheets of paper of side 40 cm would she require?

Question 20 :
A wall of length 10 m was to be built across an open ground. The height of the wall is 4 m and thickness of the wall is 24 cm. If this wall is to be built up with bricks whose dimensions are 24 cm × 12 cm × 8 cm, how many bricks would be required?

Question 21 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d238f59b460d7261f56a.jpeg' /> In the above image, the pillars of a temple are cylindrically shaped. If each pillar has a circular base of radius 20 cm and height 10 m, how much concrete mixture would be required to build 14 such pillars?

Question 22 :
If we have a cuboid whose length, breadth and height are 15 cm, 10 cm and 20 cm respectively, then its surface area would be:

Question 23 :
A godown measures 40 m × 25 m × 15 m. Find the maximum number of wooden crates each measuring 1.5 m × 1.25 m × 0.5 m that can be stored in the godown.

Question 24 :
State true or false: Curved surface area of hemisphere is $2\pi r^{2}$.

Question 25 :
Find the amount of water displaced by a solid spherical ball of diameter 28 cm.