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Question 215315This question is from textbook higher GCSE mathematics
: a tin of paint covers a surface area of 60m(cubed) and costs £4.50.Find the cost of painting the outside surface of a cylindrical gas holder of height 30m and radius 18m.The top of the gas holder is a flat circle.
This question is from textbook higher GCSE mathematics
Answer by RAY100(1637)   (Show Source):
You can put this solution on YOUR website! Area of cylinder = area of top and bottom and side
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A= 2(pi*r^2) + (2*pi*r*h)
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A= 2pi(18)^2 + 2pi(18)(30)
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A= 2035.75 + 3392.92
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A= 5428.67 m^2
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Cost = 5428.67 m^2 * 4.5 # / 6m^2 = 4071.5025 #
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If we do not paint bottom,,A=pi * 18^2 = 1017.876 m^2
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subtract ,,,,cost = 1017.876 * 4.5/6 = 763.41 #
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The total (without bottom) = 3308 #
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