Question

The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of white washing the walls of the room and ceiling at the rate of Rs 7.50 per m2.

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Answer 1

Answer:

Rs. 855

Step-by-step explanation:

area of the wall= 2(lb+ bh+ lh)

= 2{(5×4) +(4×3) +(5×3) m²

= 2(20+12+15)

= 2× 47

= 94m²

Area of the ceiling= l× b

= 5m× 4m

= 20m²

Therefore, Total area= 94m²+ 20m²= 114m²

So, total cost of white washing= Rs.(7.50× 114)

= Rs.855

Answer 2

Given:-

• Length (l) of room = 5m
• Breadth (b) of room = 4m
• Height (h) of room = 3m

$\sf$

It can be observed that four walls and the ceiling of the room are to be white washed.

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Total area to be white washed = Area of walls + Area of ceiling of room

$\sf \implies \: 2lh+2bh+lb$

$\sf \implies \: [2×5×3+2×4×3+5×4]$

$\sf \implies \: (30+24+20)$

$\sf \implies \: 74$

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Area = 74 m²

Cost of white wash per m² area = Rs.7.50

Cost of white washing 74 m² area

$\sf \implies \: Rs. (74×7.50)$

$\sf \implies \: Rs. 555$