The internal measures of a cuboidal room are 12 m × 8 m × 4 m. Find the total cost of whitewashing all four walls of a room, if the cost of white washing is ` 5 per m2. What will be the cost of white washing if the ceiling of the room is also whitewashed.
Answers
Answer:
2(l+b)h = LSA
2(12+8)4 =2(20)4 = 40*4 = 160m²
cost of whitewashing 4 walls =160*8 = Rs 1280
area of 5 walls = LSA+ l*b
= 160 + (12*8)
= 160 + 96
= 256m²
cost of whitewashing vd ceiling = Rs 1280 +(96*8)
= Rs 1280 + 768
= Rs 2048
↦Solution : -
Let the length of room(l) = 12m
Width of the room(b) = 8m
Height of the room(h) = 4m
Now ,
Area of four walls of the room = Perimeter of the base × Height of the room
2(l+b) × h = 2 (12+8) × 4
2(12+8) × 4 = 2(20) × 4
2(20) × 4 = 40 × 4
40 × 4 = 160
160 = 160
160m² [Answer]
So ,
Cost of White washing per m² = ₹5
Total cost of white washing four walls of room = ₹ 160 × 5
₹800
Therefore , The Total cost of White Washing four Walls of the Room is ₹800 ...
Now ,
Area of ceiling is = 12 × 8
= 96m²
Cost of Whitewashing the Ceiling = ₹96 × 5
= ₹140
So , the total cost of white washing = ₹ 800 + 480
= ₹1280 [Answer]
Therefore , Total cost of white washing is ₹1280 ..