Question

A room is 8m long 6m broad and 5.5m high it has one door ofdimension 2.5m by2m and 2 windows each of dimension 1.5m by 1m find the cost of whitewashing the walls at 3.20 per sq metre

Answer 1

lateral surface area of room=2h(l+b)
=(11×14)m^2
=154m^2
area of door=2.5m×2m=5m^2
area of window=1.5m×1m=1.5m^2
area of wall to be whitewashed=(154-5+1.5)m^2
=147.5m^2
cost of whitewashing=147.5×₹3.20=₹472

hope this will help you

Answer 2

The cost of whitewashing the walls is Rs. 467.20

Given : A room is 8m long 6m broad and 5.5m high it has one door of dimension 2.5m by 2m and 2 windows each of dimension 1.5m by 1m.

To find : The cost of whitewashing.

Solution :

We can simply solve this mathematical problem by using the following mathematical process. (our goal is to calculate the cost of whitewashing)

First of all, we have to calculate the area of the four walls of the room.

Area of four walls = [2 × (Length + Breadth)] × Height

So, by putting the available data, we get :

Area of the four walls = [2 × (8+6)] × 5.5 = 154 m²

Area of door = (Length × Breadth) = (2.5 × 2) = 5 m²

Area of windows = (Length × Breadth × Number of windows) = (1.5 × 1 × 2) = 3 m²

Area of the wall on which the whitewashing is to be done :

= Area of four walls - (Area of door + Area of windows)

= 154 - (5+3)

= 154 - 8

= 146 m²

Cost of whitewashing :

= (Area of the wall on which the whitewashing is to be done × Cost of whitewashing per sq. metre)

= (146 × 3.20)

= Rs. 467.20

(This will be considered as the final result.)

Hence, the cost of whitewashing the walls is Rs. 467.20