Question

The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs. 7.50 $m^2.$

Answer 1

Length of a room (l) = 5 m

Breadth (b) = 4 m

and height ( h) = 3 m

$\therefore \text{Area of 4 walls}=2(l+b)\times h$

$=2(5+4)\times 3=6\times 9=54m^2$

$\text{and area of ceiling}=l\times b$

$=5\times 4=20m^2$

$\therefore \text{Total area}=54+20=74m^2$

$\text{Rate of white washing}=7.50per{m}^2$

$\therefore \text{Total cost}=Rs.74\times 7.50=Rs.555$