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 painting the four walls at the rate of Rs. 10 per m2 is Rs. 15,000, find the height of the hall.[Hint: Area of the four walls = Lateral surface area]
Answer» Here we are given that perimeter of the floor of a rectangular hall = 250 m Area of four walls to be painted = 2(l + b) x h = Perimeter x h …..(i) Cost of painting the four walls at the rate of Rs. 10 per m² is Rs. 15,000 Total area which is to be painted = \(\frac { 15000 }{ 10 }\) = 1500 m² Using relation (i), we have 1500 m² = Perimeter x h ⇒ 1500 m² = 250 m x h ⇒ h = 6 m Hence, height of the room is 6 m.

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. 15,000, find the height of the hall.[Hint: Area of the four walls = Lateral surface area]

Answer»

Here we are given that perimeter of the floor of a rectangular hall = 250 m

Area of four walls to be painted

= 2(l + b) x h = Perimeter x h …..(i)

Cost of painting the four walls at the rate of Rs. 10 per m² is Rs. 15,000

Total area which is to be painted

= \(\frac { 15000 }{ 10 }\) = 1500 m²

Using relation (i), we have

1500 m² = Perimeter x h

⇒ 1500 m² = 250 m x h

⇒ h = 6 m

Hence, height of the room is 6 m.