Question

find find the cost of whitewashing the walls of a room 10 metre long 6 metre wide and 4 metre high allowing 25 square metre for doors, Windows etc at rupees 50 per square metre ​

Answer 1

1. area of cubiodal=l*b*h

Answer 2

The cost of whitewashing the walls is ₹5150.

Given data :

Length of the room is 10 metres.

Width of the room is 6 metres .

Height of the room is 4 metres.

Combined area of door and windows is 25 m².

Rate of whitewashing is rupees 50 per square metre.

- At first we have to calculate the total surface area of the four walls by the following mathematical formula :

Surface area of four walls

= Floor perimeter × Height

= {2×(length+width)}× Height

= {2×(10+6)}×4

= (2×16)×4

= 32×4

= 128 metre²

• Now,the actual surface area of the four walls for the white washing will exclude the area of the doors and windows.

• Actual surface area

= Total surface area - Combined area of doors and windows

= 128-25

= 103 metre²

• Now,the cost of whitewashing is

= Total surface area × Cost of one metre²

= 103×50

= ₹5150

• So,the total cost will be ₹5150 (answer).