The length and bredth of a hall are in the ratio `4:3` and its height is `5. 5m e t r e sdot` The cost of decorating its walls (including doors and windows) at `R s .6.60p e rs q u a r em e t r e` is `R s .5082.` Find the length and breadth of the room.

Explanation

let `l=4xm`
and `b=3xm`

area of walls=(total cost)/(rate)

`= Rs 5082/6.60Rs`

`=770m^2`

or,`2h(l+b)=770`

`2xx5.5(7x)=770`

`x=10`

so `l=40m`

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