Q20 of 70 Page 19

The altitude of a circular cylinder is increased six times and the base area is decreased one-ninth of its value. The factor by which the lateral surface of the cylinder increases, is

Given,


Let Initial height of cylinder = h


Initial curved surface area = 2πrh


Now altitude become = 6h


And base area =


In first case radius = r


In second case it become =


So , area =


Factor by which lateral surface of cylinder increase =

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