Question

a room is twice as long as it wide . the cost of carpenting the floor at 40 paise per square metre is rs 88.20 and that of painting its 4 walls at 9 paise per square metre is rs 56.70 find the dimensions of the room

Answer 1

Answer:

Let width=x

so, length=2x

Floor area= 2x^2 (L×W)

so, 2x^2×40/100= 88.20

or, 2x^2=8820/40

or, x^2=882/8

or, x^2=441/4

or, x= √(441/4)

or, x=21/2= 10.5 m

W=10.5m

L= 2×10.5= 21m

Now,

Let height =h

{2(L×h)+2(W×h)}×9/100 =56.70

or,{ (2×21×h)+(2×10.5×h)} = 5670/9

or,63h= 630

or, h=630/63=10 m