Question

Length of class-room is two times its height and breadth is $1\frac{1}{2}$ times its height. The cost of white washing the walls at the rate of $Rs.1.60$ per $m^2$ is $Rs.179.20$. Find the cost of tiling the floor at the rate of $Rs.6.75$ per $m^2$.

Answer 1

Let the height of the class room be $x$ m.
Then, the length $=2x$ m and breadth = $\frac{3}{2}x$
Given, cost of white washing the walls @Rs 1.60 per $m^2=Rs.179.20$
$⟹2(l+b)\times h\times 1.60=179.20⟹2(2x+\frac{3}{2}x)\times x=112⟹\frac{7}{2}{x}^2=56⟹x^2=16⟹x=4m$
Therefore, height of the classroom $=4m$, length $=8m$ and breadth $=6m$
Now, area of floor tile $=l\times b=8\times 6=48m^2$
So, the cost of tiling the floor at Rs 6.75 per $m^2=48\times 6.75=Rs.324$