求救！咋樣，可以成攻救人？
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4 people need to cross a bridge before it collapese,  they have seventeen minutues befor the collapse. there is only one flashlight and each must have the light to cross. the bridge can only hold 2 people at a time ,can you save them ？ 1. 1 old man （need 10 minute to cross） 2. 40  year old woman （need 5 minute to cross） 3. 20 year old （need 2 minute to cross）

所有跟帖： 

• 回複：求救！咋樣，可以成攻救人？ -guest007- ♀ (69 bytes) () 09/28/2010 postreply 18:06:11

• 回複：回複：求救！咋樣，可以成攻救人？ -piffle- ♀ (658 bytes) () 09/29/2010 postreply 12:31:33

• Another solution: switching P1 and P2 also works -newers- ♂ (0 bytes) () 10/03/2010 postreply 07:32:54

• 1. old + yong (10), 2. Young back(2) 3. Two go (5) -mimiwiwi- ♀ (0 bytes) () 09/30/2010 postreply 02:00:10

• 17 minutes is up, you still have 1 person left behind -oops_yz- ♀ (0 bytes) () 10/01/2010 postreply 09:19:53

• 回複：求救！咋樣，可以成攻救人？ -m6412- ♂ (164 bytes) () 10/04/2010 postreply 18:38:54