Advertisements
Advertisements
प्रश्न
The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four walls at the rate of ₹ 10 per m2 is ₹ 15,000, find the height of the hall.
Advertisements
उत्तर
Let the length, breadth, and height of the rectangular hall be l m, b m, and h m respectively.
The perimeter of the floor of hall = 2(l + b)
250 m = 2(l + b)
(l + b) = `250/2 = 125` cm ...(i)
Area of four walls = Area of cuboid – Area of floor – Area of top
= 2 (lb + bh + hl) – (l x b) – (l x b)
= 2(lb) + 2 (bh) + 2(hl) – 2lb = 2 lh + 2 bh
= 2h(l + b)
= 2h x 125 [From (i)]
= 250h m2
Area of four walls = 250h m2
Cost of painting 1 m2 area = ₹ 10
Cost of painting 250h m2 area = ₹ 10 x 250h = 2500h
15000 = 2500h
h = `15000/2500`
The height of the hall is 6 m.
APPEARS IN
संबंधित प्रश्न
Hameed has built a cubical water tank with lid for his house, with each other edge 1 .5 m long. He gets the outer surface of the tank excluding the base, covered with square tiles of side 25 cm. Find how much he would spend for the tiles, if the cost of tiles is Rs. 360 per dozen.
A cuboidal wooden block contains 36 cm3 wood. If it be 4 cm long and 3 cm wide, find its height.
Find the weight of solid rectangular iron piece of size 50 cm × 40 cm × 10cm, if 1 cm3 of iron weighs 8 gm.
A cuboidal block of silver is 9 cm long, 4 cm broad and 3.5 cm in height. From it, beads of volume 1.5 cm3 each are to be made. Find the number of beads that can be made from the block.
How much clay is dug out in digging a well measuring 3 m by 2 m by 5 m?
How many planks each of which is 3 m long, 15 cm broad and 5 cm thick can be prepared from a wooden block 6 m long, 75 cm broad and 45 cm thick?
An 8 m long cuboidal beam of wood when sliced produces four thousand 1 cm cubes and there is no wastage of wood in this process. If one edge of the beam is 0.5 m, find the third edge.
Find the surface area of a cuboid whose length = 10 cm, breadth = 12 cm, height = 14 cm.
The perimeter of a floor of a room is 30 m and its height is 3 m. Find the area of four walls of the room.
Show that the product of the areas of the floor and two adjacent walls of a cuboid is the square of its volume.
The areas of three adjacent faces of a cuboid are x, y and z. If the volume is V, prove that V2 = xyz.
The dimensions of a room are 12.5 m by 9 m by 7 m. There are 2 doors and 4 windows in the room; each door measures 2.5 m by 1.2 m and each window 1.5 m by 1 m. Find the cost of painting the walls at Rs 3.50 per square metre.
The area of the floor of a room is 15 m2. If its height is 4 m, then the volume of the air contained in the room is
The sum of the length, breadth and depth of a cuboid is 19 cm and its diagonal is ` 5 sqrt(5)` cm. Its surface area is
The dimensions of a Cinema Hall are 100 m, 60 m, and 15 m. How many persons can sit in the hall if each requires 150 m3 of air?
The volume of a cuboid is 7.68 m3. If its length = 3.2 m and height = 1.0 m; find its breadth.
Find the length of each edge of a cube, if its volume is :
(i) 216 cm3
(ii) 1.728 m3
A tank 30 m long, 24 m wide, and 4.5 m deep is to be made. It is open from the top. Find the cost of iron-sheet required, at the rate of ₹ 65 per m2, to make the tank.
The sum of the radius and the height of a cylinder is 37 cm and the total surface area of the cylinder is 1628 cm2. Find the height and the volume of the cylinder.
The diameter of a garden roller is 1.4 m and it 2 m long. Find the maximum area covered by its 50 revolutions?
The curved surface area and the volume of a toy, cylindrical in shape, are 132 cm2 and 462 cm3 respectively. Find, its diameter and its length.
The total surface area of a cuboid is 46m2. If its height is 1m and breadth 3m, find its length and volume.
A square plate of side 'x' cm is 4 mm thick. If its volume is 1440 cm3; find the value of 'x'.
375 persons can be accommodated in a room whose dimensions are in the ratio of 6 : 4 : 1. Calculate the area of the four walls of the room if the each person consumes 64m3 of air.
The dimensions of a cuboidal box are 6 m × 400 cm × 1.5 m. Find the cost of painting its entire outer surface at the rate of ₹ 22 per m2.
