The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four
walls at the rate of 10 per mist 15000 find the height of the hall
Hint: Area of the four walls Lateral surface area)
Answers
Given:
- Floor of rectangular hall has perimeter of 250 m
- Cost of painting four walls at the rate of Rs 10 per m² is Rs 15000
To find:
Height of hall = ?
Solution:
Let l = length
b = breadth
h = height
Perimeter of floor of a rectangular = 250
2(l + b) = 250
Area of four walls can be found by subtracting the area of cuboid , area of floor and area of top surface.
Area of four walls = Area of cuboid - Area of floor - Area of top surface
= 2(lb + bh+ lh) - lb - lb
= 2lb + 2bh + 2lh - 2lb
= 2bh + 2lh
= 2h(l + b)
= 2h (125)
= 250h m²
Cost of painting 1m² is Rs 10
Cost of painting 250h m² is Rs 2500h
Since, we get to know that cost of painting all is Rs 15000
15000 = 2500h
Answer:
Thus, height of Hall is 6m
Answer:
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Answer:−
Given:
Floor of rectangular hall has perimeter of 250 m
Cost of painting four walls at the rate of Rs 10 per m² is Rs 15000
To find:
Height of hall = ?
Solution:
Let l = length
b = breadth
h = height
Perimeter of floor of a rectangular = 250
2(l + b) = 250
\begin{gathered} \\ \\ l + b = \dfrac{250}{2} \\ \\ l + b = 125 \: m \\ \\ \end{gathered}
l+b=
2
250
l+b=125m
Area of four walls can be found by subtracting the area of cuboid , area of floor and area of top surface.
Area of four walls = Area of cuboid - Area of floor - Area of top surface
= 2(lb + bh+ lh) - lb - lb
= 2lb + 2bh + 2lh - 2lb
= 2bh + 2lh
= 2h(l + b)
= 2h (125)
= 250h m²
Cost of painting 1m² is Rs 10
Cost of painting 250h m² is Rs 2500h
Since, we get to know that cost of painting all is Rs 15000
15000 = 2500h
\begin{gathered} \\ \\ \dfrac{15000}{2500} = h \\ \\ h = 6 \: m\end{gathered}
2500
15000
=h
h=6m
Answer:
Thus, height of Hall is 6m