Question

The length, breadth and height of a room are 5m, 4m & 3m respectively, the cost of colour washing its four walls and ceiling at the rate of Rs. 10 per square meter is Rs. ____________ *


a)120

b)740

c)940

d)None of these

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Answer 1

Answer:

c) ₹740

Step-by-step explanation:

Lateral surface area of cuboid = 2(lb+bh+lh) - lb

                                                   = 2{(5)(4)+(4)(3)+(5)(3)} - (5)(4)

                                                   = 2{20+12+15}-20

                                                   = 2{47}-20

                                                   = 94-20

                                                   = 74$m^{2}$

Cost of painting the room = (cost)(lateral surface area of room in metres)

                                           = (10)(74)

                                           = ₹740