In the 16th century, Niccolò Tartaglia proposed the following problem.
"Three young couples want to cross a river. Only a small boat that can carry two people is available.
The men are extremely jealous, and would never accept to leave their bride with a man if they are not present as well. How many passages over the river are necessary?"
Nine passages or crossings. ------------answer.Originally Posted by Singular
Let us call the 3 young couples, A and A', B and B', C and C'
The primes are the brides or ladies.
The banks of the river are the near bank (where they are at first) and the far bank (where they want to go).
1st passage: A and B ride for the far bank. Both men.
A' and B' are with C and C', so no jealousy here.
A is left at the far bank, while...
2nd passage: ...B rides alone back to near bank.
3rd passage: A' and B' ride for the far bank. Both ladies.
A' is left at the far bank with her husband A, while...
4th passage: ...B' rides alone back to near bank.
5th passage: B and C go for the far bank. Both men.
B' and C' are left on the near bank.
B is left at the far bank, with the couple A and A', while...
6th passage: ...C goes back alone to the near side.
At the near side now are B', C and C'. No jealousy. B' is not alone with C.
7th passage: C and C' go for the far bank.
B' is left alone at the near bank.
8th passage: B goes back alone to the near bank to fetch his bride.
9th passage: B and B' cross to the far bank, and all 3 couples are at the far bank now.
Eventhough C is together with his bride C'(while A and B crossing the river), A and B would never accept to leave A' and B' with a man which is C if they (A&B) are not present. Like I said the men are extremely jealous.
So the answer is 11 passages.
First let say the two side of the river is X and Y and A,B,C are men ; A', B' C' are women
1.B' and A' cross the river, A' is left on Y
2.B' rides back to X
3.C' and B' cross the river, B' is left
4.C' rides back
5.A and B cross the river, A is left
6.B and B' rides back
7.B and C cross the river, both of them are left
8.A' rides back alone..........................>>now there are 3 men on the side Y
and 3 women on side X
9.A' and B' cross the river, A' is left on Y
10. B' rides back to X
11. B' and C' cross to Y......................................>>>now three couples are on far bank(Y)
By the way two couple requires 5 passages and for 4 or more there's no solution..
Ummm, I see how miserable the lives of those three young couples.
Any of the brides cannot go to market, church, work, family, friends, wherever if her husband is not with her.
I'd give any of them ladies 4 months max to either go insane or kill herself. Yeah.
Or the husband.
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