The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four walls at the rate of Rs 10 per m2 is Rs 15000, find the height of the hall.
[Hint: Area of the four walls = Lateral surface area]
Let length, breadth, and height of the rectangular hall be l m, b m, and h m respectively
Area of four walls = 2lh + 2bh = 2(l + b) h
Perimeter of the floor of hall = 2(l + b)
= 250 m
Area of four walls = 2(l + b) h
= 250h m2
Cost of painting per m2 area = Rs 10
Cost of painting 250h m2 area = Rs (250h × 10)
= Rs 2500h
However, it is given that the cost of paining the walls is Rs 15000
15000 = 2500h
h = 6
Therefore, the height of the hall is 6 m