25 into 15 best min fragment found: 25/4
  Cut up 25 sticks of length 15 like this:
    5 x (15/2 + 15/2)
    20 x (25/4 + 35/4)
  Reassemble as 15 sticks of length 25 like this:
    10 x (15/2 + 35/4 + 35/4)
    5 x (25/4 + 25/4 + 25/4 + 25/4)