How to Beat River Test on the BlackBerry PlayBook

“River Test” is a new game available for free in the BlackBerry App World for the PlayBook tablet.  The app is actually a virtual riddle and claims that it is used by employers in Japan during the employee interview process.  It further states that only 10% of the human race can solve this.

I downloaded this test and disagree with the sentence above.  Given enough time, I think anyone can successfully finish this if they put their mind to it.  I do, however, feel that most could not complete it within 10 minutes on their first try.


The rules are simple.  There are 8 people, a small raft and a river.  The 8 people are:





Son 1

Son 2


Daughter 1

Daughter 2


The objective of this riddle is to have all of the people cross the river.  However, it is made difficult due to the following rules:


1. The cop must always be present with the prisoner or else the prisoner will attack

2. The Father can never be left with any of the daughters without the Mother present

3. The Mother can never be left with any of the sons without the Father present

4. Only 2 people can be on the raft at one time

5. Only the Cop, Father and Mother can operate the raft, so one of them must always accompany others


It sounds easy, but for some, it seems impossible at first.  I was lucky, I did it in about 4 and a half minutes on my first attempt.  For those who are completely stumped, I thought I would provide you with the solution.  Keep in mind that there are many ways to do this and below just lists the way I did it when I was taking notes to share.


1. Cross the Cop and Prisoner

2. Bring the Cop back

3. Cross the Cop and Son 1

4. Bring both the Cop and Prisoner back

5. Cross the Father and Son 2

6. Bring Father back
7. Cross the Father and Mother

8. Bring the Mother back

9. Cross the Cop and Prisoner

10. Bring the Father back

11. Cross the Father and Mother

12. Bring the Mother back

13. Cross the Mother and Daughter 1

14. Bring the Cop and Prisoner back

15. Cross the Cop and Daughter 2

16. Bring the Cop back

17. Cross the Cop and Prisoner


You have now crossed over all 8 people without anyone getting attacked.  Enjoy!