Let length , breadth, and height of the rectangular hall be l m, b m, and h m respectively.
Area of four walls = 2h + 2bh
= 2(l+b) h
Perimeter of the floor of hall = 2 (l+b)
∴ Area of four walls = 2 (l+b)h=250 h 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 painting the walls is Rs 15000.
∴ 15000 = 2500h
Therefore, the height of the hall is 6 m.