Over a year ago we posted the Fox, Chicken and Corn puzzle which can be found here. It is getting a lot of interest because it is hinted at in a TV commercial. With that in mind we have another puzzle along the same lines - a river crossing where things (or in this case people) can't be left together.
Three husbands and their wives must cross a river and the boat available can only carry two people. No husband can leave his wife in the company of another man if he is not there, and this restriction applies even if the wife of the other man is present.
How can they cross the river without any man leaving his wife with another man? Remember both men and women can row.
The best way to show this is the table below, where ABC are men and abc their corresponding wives.
This Bank Boat Direction Far Bank
AaCc Bb > -
AaCc B < b
ABC ac > b
ABC a < bc
Aa BC > bc
Aa Bb < Cc
ab AB > Cc
ab c < ABC
b ac > ABC
b B < AaCc
- Bb > AaCc