Question

The floor of a rectangular hall has a perimeter 250m.If the cost of painting of the four wall at the rate of rupees 10 per m square is rupees 15000, find the height of the wall

Answer 1

2 x (l+b) = 250

( l + b ) = 250/2

l + b = 125

rate - 10/sq.m

cost - 15000

area = cost/rate

area = 15000/10

= 1500 sq.m

2 x h x ( l + b ) = 1500

but ( l + b ) = 125

So, 2 x 125 x h = 1500

250 x h = 1500

h = 1500/250

h = 6m

Hence Proved.

Answer 2

Step-by-step explanation:

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

Cost of painting per square meter area = Rs.10

Cost of painting 250h square meter area = Rs (250h×10) = Rs.2500h

However, it is given that the cost of paining the walls is Rs. 15000.

15000 = 2500h

Or h = 6

Therefore, the height of the hall is 6 m.