Question

The cost of white-washing the four walls of a room is Rs. $100.$ Calculate the cost of white-washing a room twice in length and breadth and one fourth in height.

Answer 1

Let, length : $l$

breadth : $b$

and height : $h$

Then,

Area of four walls : Cost

$2h(l+b)$ : Rs. 100

$\therefore$ the cost of white-washing the area $=2\times \frac{h}{4}(2l+2b)$

$h(l+b)$ will be $\frac{1}{2}\times Rs.100$ = Rs. 50