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 the ceiling at the rate of Rs 7.50 per m2


It can be observed that four walls and the ceiling of the room are to be whitewashed

The floor of the room is not to be white-washed

The area to be white-washed = Area of walls + Area of the ceiling of the room

= 2lh + 2bh + lb

= [2 × 5 × 3 + 2 × 4 × 3 + 5 × 4] m2

= (30 + 24 + 20) m2

= 74 m2

Cost of white-washing per m2 area = Rs 7.50

Cost of white-washing 74 m2 area = Rs (74 × 7.50)

= Rs 555

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