Question

The floor of a rectangular hall has a perimeter 150m. If the cost of painting the four walls at the rate of Rs. 10 per m2 is Rs. 9000, find the height of the hall.​

Answer 1

Answer:

Height is 6 m .

Step-by-step explanation:

Perimeter is =2(a+b)

                    =150m

So,                a+b=75

or,                 a=75-b

Now, total area of 4 walls =9000/10

                                           =900

Let height be c : we get:

                     2(ac+bc)=900

                         ac+bc=450

                  (75-b)c+bc=450

                                 C=450/75

                                    =6 m

Therefore, the height of the hall is 6 m.

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i hope it will helps you friend

C=450/75=6m

Answer 2

Answer :

    Height of the hall is 6 m

Solution :

Let, length = l m

      width = w m

      height = h m

Perimeter of the floor = 150 m (given)

  ⇒ 2 (length + widhth) = 150

  ⇒ 2 (l + w) = 150

  ⇒ l + w = 75 .....(i)

Area of the four walls

  = 2 * height * (length + width)

  = 2h (l + w)

  = 2h * 75 m²

  = 150h m²

Cost of painting four walls = Rs 9000 (given)

  ⇒ 150h × 10 = 9000

  ⇒ 1500h = 9000

  ⇒ h = 6

         ∴ the height of the hall is 6 m