# NCERT Mathematics Class 9 Exemplar Ch 13 Surface Areas and Volumes Part 4

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**Exercise 13.3**

Q.1. Metal spheres, each of radius 2 cm, are packed into a rectangular box of internal dimensions. When 16 spheres are packed the box is filled with preservative liquid. Find the volume of this liquid. Give your answer to the nearest integer.

Answer:

Q.2. A storage tank is in the form of a cube. When it is full of water, the volume of water is. If the present depth of water is, find the volume of water already used from the tank.

Answer:

Q.3. Find the amount of water displaced by a solid spherical ball of diameter, when it is completely immersed in water.

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Q.4. How many square metres of canvas is required for a conical tent whose height is and the radius of the base is?

Answer:

Q.5. Two solid spheres made of the same metal have weights and, respectively. Determine the radius of the larger sphere, if the diameter of the smaller one is.

Answer:

Q.6. A school provides milk to the students daily in a cylindrical glasses of diameter. If the glass is filled with milk upto a height of, find how many liters of milk is needed to serve 1600 students.

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Q.7. A cylindrical roller in length, in radius when rolled on a road was found to cover the area of. How many revolutions did it make?

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Q.8. A small village, having a population of, requires 75 liters of water per head per day. The village has got an overhead tank of measurement For how many days will the water of this tank last?

Answer: 40 days

Q.9. A shopkeeper has one spherical laddoo of radius. With the same amount of material, how many laddoos of radius can be made?

Answer: 8 laddoos

Q.10. A right triangle with sides 6 cm, 8 cm and 10 cm is revolved about the side 8 cm. Find the volume and the curved surface of the solid so formed.

Answer: