Problem: the volumes of two cones are in the ratio 1 : 10 and the radii of the cones are in the ratio of 1 : 2 . what is the length of the wire ? 
Options: ['a ) 2 : 5', 'b ) 2 : 9', 'c ) 2 : 2', 'd ) 2 : 9', 'e ) 2 : 1']
a