Q12 of 47 Page 1

in Fig. 5, a tent is in the shape of a cylinder surmounted by a conical top of same diameter. If the height and diameter of cylindrical part are 2.1 m and 3m respectively and the slant height of conical part is 2.8 m, find the cost of canvas needed to make the tent if the canvas is available at the rate of Rs. 500/sq. metre. (Use π = 22/7)

Let radius of cylinder = radius of cone = r




Height of cylinder, h = 2.1 m


Slant height of cone, l = 2.8 m


Canvas needed to make tent = CSA of Cone + CSA of Cylinder [CSA = curved surface area]


= rl + 2πrh


= πr(l + 2h)





= 33 m2


Cost of 1 m2 canvas = 500 Rs


Cost of 23.1 m2 = 33(500) = 16500 Rs


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