Question

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

Answer 1

Answer:

Let the height be h

Perimeter=250m= 2(l+b)

Total cost of painting=15000

Total area painted(four walls) =15000/10=1500m sq.

Let's take the room as a cuboid,

Then, its lateral area will be the area of its four walls which is = 2h(l+b)=1500m sq.

Then lateral surface area of cuboid=2h(l+b)

=2(l+b) h=1500m

=250xh=1500m sq.

=h=1500m/250m

h=6m

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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.