Question

The length of a room is double it's breadth . The cost of colouring the ceiling at Rupee 25 per sq m is Rupee 5000 and the cost of painting the four walls at Rupee 240 per sq m is Rupee 64800 . Find the height of the room .

Please tell Right answer ​

Answer 1

Answer:

h = 4.5 m

Step-by-step explanation:

celling

let the length of room be x

b = 2x

total cost of colouring the celling = rs 5000

cost for 1 m sq. = rs 25

area = 5000/25 = 200 m sq.

area of celling = 200 m sq

L × b = 200 m sq

x * 2x = 200 m sq

2 x sq = 200

x sq = 100

x = √100

x = 10 m

FOUR WALLS

cost of colouring 1 m sq = rs 240

total cost of colouring = 64800

area = 64800/240

= 270 m sq

area of four walls = c.s.a. of cuboid

area of four walls = 270 m sq

2 bh +2 hl = 270 m sq

2 h ( l + b ) = 270

2 h ( 10 + 20 ) = 270

h (30 ) = 135

h = 135 /30

h = 4.5 m

Answer 2

Let, the breadth of room be x m.

Length = 2x m

Area of ceiling = 5000/25

Length × breadth = 200

2x × x = 200

x^2 = 100

x = 10 m

Breadth = 10m

Length = 20 m

Area of four walls = 64800/240

2lh + 2bh = 270

2× 20 × h + 2 × 10 × h= 270

40h + 20h = 270

h = 270/60

h = 4.5 m Ans