hey Tapas, are you sure there is nothing missing in this question and you haven't missed on anything... ?
is this the full question stem?
I'm looking for a solution just from the given information.
I've thought in this way : for 2 units of upper radius , 5 units [or 10 unit] of upper circumference goes. Problem is this relation won't work for the lower portions of radius and circumference. .............Isn't it possible to make/create any kind of relation in between ? .......anything logical?