The cost of papering four walls of a room at `70` paise per squar emter` is R s .157.50. The height of the room is 5 metre cdot Find the length and the breadth of the room if they are in the ratio 4:1

Explanation

total area of wall=total cost/rate

`=157.50/0.70`

`=225m^2`

or, `2h(l+b)=225`.....(1)

let `l=4x`
`b=x`and given `h=5m`

put in eq (1)

`2xx5(4x+x)=225`

`x=4.5`

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