Question

The length , breadth and height of a room are 5 cm , 4 cm 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 per m${}^2$.

• A. 444
• B. 555
• C. 666
• D. 777

Answer 1

The correct option is B 555

Area to be white washed does not include the floor.

$\therefore$, area to be white washed

$=$ Area of four walls $+$ area of the ceiling

$=2(l+b)\times h+l\times b$

$=[2(5+4)\times 3+5\times 4]m$

$=54+20m^2$

$=74m^2$

Cost of white washing $=Rs7.50\times 74=Rs555$