The length, breadth and height of a room are 5 m, 4 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs 7.50 per m².

3

(a)

The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four walls at the rate of Rs 10 per m² is Rs 15000, find the height of the hall. 

3

(a)

The paint in a certain container is sufficient to paint an area equal to 9.375 m². How many bricks of dimensions 22.5 cm \(\times\) 10 cm \(\times\) 7.5 cm can be painted out of this container?

3

(a)

The curved surface area of a right circular cylinder of height 14 cm is 88 cm². Find the diameter of the base of the cylinder.

3

(a)

It is required to make a closed cylindrical tank of height 1 m and base diameter 140 cm from a metal sheet. How many square meters of the sheet are required for the same?

3

(a)

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.
(i) inner curved surface area,
(ii) outer curved surface area,
(iii) total surface area.

3

(a)

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.

3

(a)

Find:
(i) the lateral or curved surface area of a closed cylindrical petrol storage tank that is 4.2 m in diameter and 4.5 m high.
(ii) how much steel was actually used if \(\frac { 1 }{ 12 } \) of the steel actually used was wasted in making the tank?

3

(a)

In figure, you see the frame of a lampshade. It is to be covered with a decorative cloth. The frame has a base diameter of 20 cm and height of 30 cm. A margin of 2.5 cm is to be given for folding it over the top and bottom of the frame. Find how much cloth is required for covering the lampshade.
              

3

(a)

Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm. Find its curved surface area.

3

(a)

What length of tarpaulin 3 m wide will be required to make conical tent of height 8 m and base radius 6 m? Assume that the extra length of material that will be required for stitching margins and wastage in cutting is approximately 20 cm. (Use \(\pi \) = 3.14).

3

(a)

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 m².

3

(a)

A joker's cap is in the form of a right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 10 such caps.

3

(a)

A bus stop is barricaded from the remaining part of the road, by using 50 hollow cones made of recycled cardboard. Each cone has a base diameter of 40 cm and height 1 m. If the outer side of each of the cones is to be painted and the cost of painting is Rs12 per m², what will be the cost of painting all these cones? (Use \(\pi =3.14\) and take \(\sqrt { 1.04 } =1.02\))

3

(a)