Question

the area of the four walls in a room is 120 m square the length of twice the breadth if the height of the room is 4 m find the area of the floor

Answer 1

given
area of room is 120

let breadth be x

then length =twice the breadth
l. = 2x

height. = 4m

According to problem

area of four walls = 120m^2

2h(l+b) = 120

2×4 ( 2x +x ) = 120

8 ( 3x ) = 120

3x. = 15

x. = 5

Answer 2

Answer:

Area of the floor = 50m²

Step-by-step explanation:

Given, Area of four walls in a room = 120m²

                        height of room (h) = 4m

Here given that length is twice of the breadth

Then,  

    Let breadth of room (b) = x m

    length of room (l) = 2x m

we know that,

Area of four walls in a room = 2 ( l + b ) * h

               120 = 2 ( 2x + x ) * 4

Dividing by 8 on both sides, we get,

                 15 =  3x

Dividing by 3 on both sides, we get,

                 5 = x

             ⇒ x = 5

Now, breadth of room = x = 5m

length of room = 2x = 2*5 = 10

Now area of floor = length*breadth

                             = 10*5  

                             = 50m²