~ a neat little riddle ~

Spooner

Lifer
Jan 16, 2000
12,025
1
76
It is a dark and stormy night, and foggy, and rather cold. In the middle of nowhere a family battle the elements to get home, they have been walking for miles when they get to 'the great ravine'. For miles in either direction there is only one crossing a very small rickety rope bridge, the family must cross the bridge, your aim is to work out in what order they should cross to get across the bridge in the shortest possible time. Now here are the problems, firstly as the bridge is so old they can only risk two people crossing it at once, also stupidly they only have one torch. No more than two people may cross the bridge at one time and because it is so foggy and there are planks missing from the bridge one of them must be carrying the torch. The ravine is too wide to throw the torch across so someone is going to have a busy night going back and forth.

DATA : There are four members of the family, a boy who is quick who can cross the bridge in only one minute, his sister who is a little slower who takes two, his mother who is slower still at five minutes, and finally the grandmother who is getting on a bit and takes a whopping ten whole minutes to cross.

You may not like the family (who takes their grandmother out for a walk in the middle of a storm?) but they need your help, get them across as fast as you can, any slower than the fastest they can cross.

Once you've worked out the best way you believe for them crossing (you may need a pen and paper) enter your answer as follows (read carefully).

Each time you make a crossing.. display it in pairs, enter them as follows. Put each crossing like this, if you were sending the boy and the mother across type bm5 (Boy/Mother 5 mins.. since the mother is the slowest), or if the sister and the grandmother sg10 (i.e. in alphabetical order), put them in order of how they cross and don't forget the return journeys, i.e. bm5 + b1. Then once they have all crossed type in your total minutes. Now there is different ways of reaching the final answer and this has been accounted for so just work it out, and type it in, if your right there will be instant sex appeal just waiting for you. To help you here is an example of how NOT to do it (so you see how to type it in) : bg10 + g10 + gs10 + g10 + gm10 = 50 total mins

You may begin...
 

Spooner

Lifer
Jan 16, 2000
12,025
1
76
Originally posted by: 00Jones
The answer is 15.....
too damn long
actually, tough guy, it isn't.
rolleye.gif

 

ingenuiti

Member
Aug 1, 2002
189
0
0
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14
 

isaacmacdonald

Platinum Member
Jun 7, 2002
2,820
0
0
Originally posted by: ingenuiti
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14

ahh. nice
 

dullard

Elite Member
May 21, 2001
26,185
4,844
126
Originally posted by: ingenuiti
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14

How does the boy cross on 2nd trip without a torch? No 17 minutes is the correct answer (and there are two ways of doing that).

isaacmacdonald had one of the ways: BS2 B1 MG10 S2 BS2 = 17

The other way is: BS2 S2 MG10 B1 BS2 = 17.
 

isaacmacdonald

Platinum Member
Jun 7, 2002
2,820
0
0
Originally posted by: isaacmacdonald
Originally posted by: ingenuiti
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14

ahh. nice

oops, except that boy can't cross cause he doesn't have a torch

 

conjur

No Lifer
Jun 7, 2001
58,686
3
0
Originally posted by: ingenuiti
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14

There must be a pair crossing the bridge.
 

Aharami

Lifer
Aug 31, 2001
21,205
165
106
Originally posted by: ingenuiti
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14

no can do. the torch has to come back after 1st trip. boy cannot cross (2nd trip) without torch
 

samgau

Platinum Member
Oct 11, 1999
2,403
0
0
Originally posted by: ingenuiti
14 Minutes:

1st Trip - Grandmother/Mother = 10 minutes
2nd Trip - Boy (One way to retrieve Torch) = 1 minute
3rd Trip - Boy (Returns with Torch to sister = 1 minute
4th Trip - Boy/Sister = 2 mintues

Total Minutes = 14

that could have been better but the boy cannot cross without the torch....
 

thereds

Diamond Member
Apr 4, 2000
7,886
0
0
Kill the grandmother and be outta there before the sh|t hits the floor or ravine in this case.
 

dullard

Elite Member
May 21, 2001
26,185
4,844
126
There of course is the alternate method - but more dangerous.

BS2 + B1 + GM10 (where they set the rope on fire in places along the way so that the boy can see) + B1 (hopefully fast enough that the ropes haven't burned through) = 14 minutes.
 

isaacmacdonald

Platinum Member
Jun 7, 2002
2,820
0
0
Originally posted by: dullard
There of course is the alternate method - but more dangerous.

BS2 + B1 + GM10 (where they set the rope on fire in places along the way so that the boy can see) + B1 (hopefully fast enough that the ropes haven't burned through) = 14 minutes.

lmfao.
 

jfall

Diamond Member
Oct 31, 2000
5,975
2
0
I remember a flash version of this exact riddle.. anyone know where it is? there was a few other good ones on the site too. It was posted here many moons ago.

Oh and here is another riddle for ya's:

A magician must cross a bridge carrying three gold pieces. He weighs exactly 68 kilograms, and each piece of gold weighs one kilogram. The bridge can carry no more than 70 kilograms or it will break. How does he cross the bridge safely, without throwing or dragging the gold across?
 

fatjohnny

Member
Sep 30, 2003
42
8
71
The magician juggles the three gold pieces, therefore one is always in the air and no more than two (2kg) is in his possession at one time.

68kg + 2kg (and the other kg is always in the air) = 70kg

Fat Johnny