Problem: the area of the floor of a room is 20 m 2 that of a longer wall 15 m 2 and of the shorter wall 12 m 2 , find the edge of the new cube ? 
Options: ['a ) 450 m 3', 'b ) 100 m 2', 'c ) 60 m 3', 'd ) 400 m 3', 'e ) 500 m 3']
c