# CBSE Class 10-Mathematics: Chapter – 13 Surface Areas and Volumes Part 13 (For CBSE, ICSE, IAS, NET, NRA 2022)

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**Question 27**:

A solid iron pole consists of a cylinder of height and of base diameter which is surmounted by a cone high, find the mass of the pole. Given that of iron has mass approx.

**Answer**:

For cylinder

For cone

Volume of pipe volume of cylindrical portion volume of cone

**Question 28**:

cubes each of volume are joined end to end. Find the surface area of the resulting cuboid.

**Answer**:

Two cubes joined end to end, we get cuboid

Surface area of cuboid

**Question 29**:

Kuldeep made a bird bath for his garden in the shape of a cylinder with a hemi spherical depression at one end. The height of the cylinder is and its radius is . Find the total surface area of the birdbath.

**Answer**:

Let h be the height of cylinder and r be the common radius of the cylinder and hemisphere.

Total surface area of bird bath C. S. A. of cylinder C. S. A. of hemisphere

**Question 30**:

A vessel is in the form of an inverted cone. Its height is and radius of its top, which is open, is it is filled with water up to brim. When lead shots each of which is a sphere of radius , are dropped into the vessel. One-fourth of the water flows out. Find the number of lead shots dropped.

**Answer**:

Radius of lead shot

Radius of cone

Let be numbers of lead shots are dropped

volume of one lead shot volume of the cone

lead shots are dropped

**Question 31**:

A cone of height and radius of base is made up of modeling clay. Find the volume of the cone.

**Answer**:

Volume of cone

**Question 32**:

cubes each of volume are joined end to end. Find the surface area of the resulting cuboid.

**Answer**:

Two cubes joined end to end, we get cuboid

Surface area of cuboid