8 Travelers river crossing puzzle

786.7K Views

We have 8 travelers:
– 1 criminal,
– 1 police man,
– 1 mother with her 2 daughters,
– 1 father with his 2 sons  (2 different families).

  • The mother wants to kill the 2 sons,
  • the father wants to kill the 2 daughters
  • The criminal wants to kill everybody

 

  • The criminal can’t kill anybody if the police man is present.
  • The mother can’t kill the sons if the father is present,
  • the father can’t kill the daughters if the mother is present.
  • The police man will not prevent the mother or the father from killing any of the children.

All eight travelers arrive at a river at the same time. They want to get across. However, there is only one boat, which can take maximal two people. The boat can only be navigated by an adult.

How can you get all eight people across the river, without anybody getting killed?river crossing puzzle

Share
Add Comment

  • 3 Answer(s)

    The criminal can’t kill anybody if the police man is present.
    Why?
    He can kill the policeman and then every others.
    But that’s not possible only because he can’t kill the policeman.
    Moreover, the policeman is always present with himself.
    So it’s clear the criminal won’t kill the policeman!!!

    1st trip: Police,Criminal will cross……………..Police will return
    2st trip: Police,1st Son will cross……………..Police and Criminal will return
    3st trip: Father,2nd Son will cross……………..Father will return
    4st trip: Father,Mother will cross……………..Mother will return
    5st trip: Police,Criminal will cross……………..Father will return
    6st trip: Father,Mother will cross……………..Mother will return
    7st trip: Mother,1st Daughter will cross…………….Police and Criminal will return
    8st trip: Police,2nd Daughter will cross……………..Police will return
    9st trip: Police,Criminal will cross……………..Nobody will return

    So, by this way everybody will cross the river!!!

    “How can you get all eight people across the river, without anybody getting killed?”
    So only we need to ensure that they will cross the river. Its not necessary that the process must be optimal though it’s already optimal,I guess .:)

    thesucker Expert Answered on 1st June 2016.

    This won’t work as per requirement, because, at Step 3, father is gone, leaving one son whom the mother can kill (because, as per the puzzle, the woman wants to kills the sons).

    on 2nd June 2016.

    both are gone read it properly this is also a good solution ..man please don’t comment without. Thinking

    on 2nd June 2016.

    Updated! Now I think u will have no problem to understand what’s going on!!
    #Viji_Pinarayi

    on 2nd June 2016.
    Add Comment

    father will take one daughter across. then come back then he will take one son across and come back .then  he will take mother across.then he will return and police man will go across with criminal.mother will return with the boat.father will take daughter accross across.and return.then father will take mother across .then police will take criminal back to the shore they started with and will get across with son
    then he will return and take criminal away with him

    Yodha Expert Answered on 1st June 2016.

    No!!
    If the father and daughter cross the river together , the father will kill the daughter!!
    So your solution is wrong!!!

    on 1st June 2016.

    Father Cannot be alone with Daughter so he and Daughter cannot cross at same time similarly Mother and son cannot be alone without father

    on 1st June 2016.

    you dont understand that one son of father is with that mother so if he kill daughter then she will kill his son .thats a deal.

    on 1st June 2016.

    if he is protecting his son then he will not kill the daughter

    on 1st June 2016.

    so my solution is right

    on 1st June 2016.

    BESIDES CRIMINAL WANT TO KILL EVERYBODY BUT HE CANT KILL POLICEMAN.SO WHAT ONE WANTS AND WHAT ONE DOES IS DIFFERENT THING ALTOGETHER

    on 1st June 2016.

    “one son of father is with that mother so if he kill daughter then she will kill his son .thats a deal.”

    …..

    It’s no ‘deal’, because it only endangers the lives of the sons (and the daughter as well). Note that it’s not “one son” but both sons are left behind when he’s taking a daughter across with him. So, in essence, it’s one daughter v/s TWO sons. How’s that a deal, except a losing one?

    on 2nd June 2016.

    Don’t you understand that mother want to save her daughter .it does not mean that she will be okay with one of them killed  when she can save both by not killing any of son.saving her childeren would be the first priority  then killing .one cannot always say 1 is less important than 2 .it depends on the content of deal too.please take a minute before posting any. Objection

    on 2nd June 2016.
    Add Comment

    1.Policeman and Criminal goes

    2.Policeman returns

    3.Policeman and Son1 Goes.

    4.Policeman and Criminal Returns.

    5.Father and Son2 Goes.

    6.Father Returns

    7.Father and Mother Goes.

    8.Mother returns.

    9.Policeman and criminal Goes.

    10.Father Returns.

    11.Father and Mother Goes.

    12.Mother Returns.

    13.Mother and Daughter1 Goes.

    14.Policeman and Criminal Returns

    15.Policeman and Daughter2 Goes.

    16.Policeman Returns

    17.Policeman and Criminal Goes

    dyj Expert Answered on 1st June 2016.

    “The criminal wants to kill everybody”
    So how the criminal ,and the police will cross the river together.
    He could kill the police!!!

    on 1st June 2016.

    according to question The criminal can’t kill anybody if the police man is present and he cannot kill policeman

    on 1st June 2016.
    Add Comment
  • Your Answer

    By posting your answer, you agree to the privacy policy and terms of service.
  • More puzzles to try-