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        riddles >> medium >> River Crossing (IV)
        
(Message started by: THUDandBLUNDER on Jun 1^st, 2003, 4:46am)

Title: River Crossing (IV)
Post by THUDandBLUNDER on Jun 1^st, 2003, 4:46am

Same scenario as River Crossing III, except now there is an island in the middle of the river.
How many crossings do you need to get FOUR couples across to the other side?

Title: Re: River Crossing (IV)
Post by redPEPPER on Jun 2^nd, 2003, 4:47am

What is a crossing? Is it from either side to the island or vice-versa? Or is it from any place to any other place? In other words, can you go from one side to the other side without stopping at the island, and count it as only one crossing?

I assumed the latter. I got 19. I think it might be optimal although I didn't look into it thoroughfully.

Title: Re: River Crossing (IV)
Post by Noke Lieu on Mar 10^th, 2004, 8:20pm

Agree with the 19, but thats not using the island.
Maybe its there as a red herring.
Or, as you point out, maybe going to the island is a half-trip.
doesn't really add much, does it? Sorry.