Question

a room is 10 m long 8m wide and 4.5 m high it has two doors each measuring 2 m by 1.2 m and three Windows each measuring 2.5 m by 1.8 m find the cost of white washing it's four walls at ₹4.40per sq m​

Answer 1

Answer:

632.28 rupees

Step-by-step explanation:

First let's

1. find the LSA of the room then
2. area of the doors then
3. area of the windows

Second let's

1. Subtract area of doors and windows from the LSA of the room
2. Calculate the cost for white wash

Its a lengthy problem

Formulae :-

• Lateral surface area of a room = 2h(l+b)
• Area of a Rectangle,a = l x b

Given,

• length,l of the room = 10m
• breadth,b of the room = 8m
• height,h of the room = 4.5m

• length,l of the doors = 2m
• breadth,b of the doors = 1.2m

• length,l of the windows = 2.5m
• breadth,b of the windows = 1.8m

• cost of white wash per sq m = 4.40rs

Now let's solve step by step :-

First :-

1) LSA of the room :-

• LSA = 2h(l+b)
• LSA = 2x4.5(10+8)
• LSA = 9(18)
• LSA = 162m²

2) area of the two doors :-

• a = 2xlxb
• a = 2 x (2 x 1.2)
• a = 4.8m²

3) area of the three windows :-

• a = 3xlxb
• a = 3x2.5x1.8
• a = 13.5m²

Second :-

1) subtract the area of doors and windows from LSA of the room :-

• 162 - 13.5-4.8
• 143.7m²

2) cost for white wash :- area x cost per sq m

• 143.7 x 4.4
• 632.28rs

Hope it helps