Question

10. A room is 8 m long, 7 m broad and 5 m high. It has 2 doors each 2 m long and 1 m
wide and 3 windows each 1.5 x 0.5 m. Find the cost of painting its four walls at
12 per m2

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Answer 1

Answer:

since the room is rectangle

therefore area of wall 1 = 8m × 5m = 40m^2 = area of wall opposite to wall1 ,say wall 4

area of wall 2 = 7m × 5m = 35 m^2 = area of wall 3

area of total walls = 2 × 40 + 2 × 35 = 150 m^2(square)

area of 2 doors = 2(2 ×1) = 4m square

area of 3 windows = 3(1.5 × 0.5) = 2.25 m^2

since the windows and doors are not to be painted

therefore 150 - 4+2.25 = 143.75 m^2 (area to be painted)

total cost = 12 × 143.75 = 1725 rupees