# cost of painting the total outside surface of a closed cylindrical oil tank at 60 paise per sq. dm is rs.237.60 . the heigth of the tank is 6 times the radius of the base of tank . find its volume correct to two decimal point...? and is que. in easy

Let r and h be the radius and height of the cylindrical tank.

Given, h = 6r

Total surface area of the closed cylindrical tank

Cost of painting = 60 paise/dm2 = Rs 0.6/dm2      (Given)

Cost of painting 1 dm2 = Rs 0.6

∴ Cost of painting 44r2 dm2 = Rs 0.6 × 44r

Total cost of painting the closed cylindrical tank = Rs 237.60        (Given)

Radius of the cylindrical tank = 3 dm

Height of the cylindrical tank, h = 6r = 6 × 3dm = 18 dm

∴ Volume of the cylindrical tank     (Upto two decimal places)

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total cost=237.6  ,  cost per sq. dm = 60 paise=0.6 rupees

therefore tsa of cylinder = 237.6/0.6=396 sq. dm

let its radius be x. Then height = 6x

TSA = 2(pi)r (r+h)=396

2*22/7*x (x+6x)=396

44 x^2 = 396               x^2 = 9

x = 3

radius = 3 dm   and    height = (6*3) = 18 dm

volume = (pi)r^2h = 22/7 *3*3*18 = 3564/7 = 509.14 cubic dm

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