Question

The length and breadth of a room are in the ratio 3 : 2. The area of the floor is
19.44 m². Find the dimensions of the room if the area of four walls is 81 m².​

Answer 1

Answer:

Correct option is A)

Let the length and breadth be 2x and 3x respectively. Then, floor area =6x

2

sq.m.

Cost of flooring at the rate of Rs. 4.00 per m

2

= Rs. 216

∴6x

2

×4=216

or x

2

=9

or x=3

∴ Length = 3x = 9m

Breadth = 2x = 6m

and Height =

2

1

× Length = 4.5 m

∴ Area of four walls = 2(length × height + breadth × height)

=2[9×4.5+6×4.5]=135m

2

Answer 2

Answer:

the required dimension of the room is 9/2 = 4.5 m

Step-by-step explanation:

Let the common factor be x

then length of the room is 3x m

breadth of the room is 2x m

area of the floor is 2x × 3x = 6x^2 m^2

given that the area of the floor is 19.44 m^2

according to question 6 x^2 = 19.44

⇒ x^2 = 81/25

⇒ x = 9/5

then length of the room is 3×(9/5) = 27/5 m

breadth of the room is 2×(9/5) = 18/5 m

let the dimension of the room is a m.

then total area of 4 walls of the room is = 2a (27/5 + 18/5) = 2a × 45/5 = 18a m^2

according to question 18a = 81

⇒ a = 9/2

therefore we get a = 9/2

hence the required dimension of the room is 9/2 = 4.5 m.