15 into 12 best min fragment found: 9/2
  Cut up 15 sticks of length 12 like this:
    3 x (6 + 6)
    12 x (9/2 + 15/2)
  Reassemble as 12 sticks of length 15 like this:
    6 x (15/2 + 15/2)
    6 x (9/2 + 9/2 + 6)