Question

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.

Answer 1

Let length, breadth and height of the hall be l, b and h respectively.

Perimeter of the floor of the hall = 2 (l + b) = 250 m.

Area of the four walls of the hall = 2h (l + b) ... (i)

Also, area of the four walls of the hall = 15000/ 10 m2

= 1500 m2 ... (ii)

From (i) and (ii), we have

2h (l + b) = 1500

⇒ h × 250 = 1500 [ 2(l + b) = 250]

⇒ h = 1500 /250 = 6

Hence, height of the hall is 6 m Ans