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        riddles >> easy >> Crossing the Bridge Problem
        
(Message started by: MQM on Jun 10^th, 2004, 9:05pm)

Title: Crossing the Bridge Problem
Post by MQM on Jun 10^th, 2004, 9:05pm

(Time yourself on this problem). Four commandos, A, B, C, & D, must cross from one end of a bridge to the other in 17 minutes - before it explodes. At most, 2 of them can cross at a time. It is dar, so their only flashlight must be carried by anyone (or pair) who is crossing. Each can cross in his/her established time:

A-1 minutes
B-2 minutes
C-5 minutes
D-10 minutes

Hint: Each pair crosses in the time of the slower member - and carrying someone else would be much, much slower. The bridge is too long to throw or shine the flashlight. Finally, obviously, all 4 of them must be at the safe end of the bridge when it blows.

Title: Re: Crossing the Bridge Problem
Post by Noke Lieu on Jun 10^th, 2004, 9:20pm

Too long to shine the flash light? Thats long.

Best ask Paul and Ringo how they did it. Or Bono and The Edge. here (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_easy;action=display;num=1039563561;start=1)

Or here:
:-[. (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_medium;action=display;num=1041593152;start=1)

or here: [ohno]. (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_medium;action=display;num=1032235917;start=15)

Don't worry- its a great puzzle. The search function isn't always the best. I try to do it one or two categories at a time. Don't know if that helps, but it seems to work for me.

Title: Re: Crossing the Bridge Problem
Post by KATRINA on Oct 14^th, 2004, 4:11pm

IT TOOK ME A WHILE BUT I GOT IT.

> 1,2 = 2
<1 = 1
>5, 10 = 10
<2 =2
> 1,2 = 2

------------
TOTAL = 17 MINUTES