Q5 of 64 Page 80

Mohan wanted to paint the walls and ceiling of a hall. The dimensions of the hall is 20m x15m x6m. Find the area of surface to be painted and the cost of painting it at ₹78 per sq. m.

Given:

l = 20m, b = 15m and h = 6m


area of walls and ceiling to be renovated = 2(lh + bh) + lb)


= 2(20(6) + 15(6)) + 20(15)


= 2(120 + 90 )+ 300


= 2(210) + 300


= 420 + 300 = 720 m2


⇒ area = 720m2


Cost of 1m = Rs 78


Cost of 720 m2 = 720× 48


= Rs 56160


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