1) Violet and Kurt cross the bridge which will take them 2 minutes because Kurt takes 2 minutes. 2) Violet returns back with the flashlight which will take 1 minute. 3) Sente and Scarlette then cross the bidge with the flashlight which will take them 10 minutes since Sente takes 10 minutes. 4) They will hand the flashlight now to Kurt who will return to pick up Violet at the other end taking 2 minutes. 5) Kurt and Violet then cross the bridge taking them 2 minutes again Thats 17 minutes..!!