Find the area of the 4 walls:
Area of the 4 walls = Perimeter of the floor x height
Area of the 4 walls = 250 x 6 = 1500 m²
Find the cost of the painting:
1 m² = Rs 8
1500 m² = 1500 x 8 = Rs 12,000
Answer: The cost of painting the 4 walls is Rs 12,000