The floor of a rectangular hall has a perimeter 250 m. If the cost of

1.	The floor of a rectangular hall has a perimeter 250 m. If the cost of panting 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.]
Answer» 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 ∴ 15000 = 2500h h = 6 Therefore, the height of the hall is 6 m.

The floor of a rectangular hall has a perimeter 250 m. If the cost of panting 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.]

Answer»

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

∴ 15000 = 2500h h = 6

Therefore, the height of the hall is 6 m.