Puzzle for 23rd Jun 2009

shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Four people are stuck on one side of the bridge and opposition Army is approaching to kill them. They should cross the bridge in minimum time possible.

Crossing time needed for each.

Soldier - 1 Min
Gunman - 2 Min
King - 5 Min
Queen - 10 Min
Torch ( As much as by the person carrying it )

Conditions:
  1. Only 2 people can cross the bridge as its not well built.
  2. Torch should be always with somebody when crossing as its dark.
  3. Torch cannot be thrown as bridge is wider than any human can throw the torch on other side.
  4. Time taken by 2 persons are of the one who is slowest.
SaswatPadhi's Avatar, Join Date: May 2009
~ Б0ЯИ Τ0 С0δЭ ~
This is a famous puzzle
[See : http://en.wikipedia.org/wiki/Beatles_Concert_Puzzle]

I think the optimal solution is :

TIME xxxxxx MOVEMENT
0
+2xxxxxxxxxSoldier and Gunman move to opposite side.
2+1xxxxxxxxxSoldier comes back.
3+10xxxxxxxxKing and Queen move to opposite side.
13+2xxxxxxxxGunman comes back.
15+2xxxxxxxxSoldier and Gunman move to opposite side.
17xxxxxxxxxxAll have crossed safely

So, minimum time to cross is 17 mins
nimesh's Avatar, Join Date: Apr 2009
Invasive contributor
The other solution would be that Gunman comes first and Soldier comes later.
But in any case, 17 would be the minimum time taken for all to cross the bridge.

Nice Reply Saswat.
mayjune's Avatar, Join Date: Jun 2009
Invasive contributor
thats two in a row....
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
I knew about this but I changed and framed the question a bit different hoping Saswat would not know it
SaswatPadhi's Avatar, Join Date: May 2009
~ Б0ЯИ Τ0 С0δЭ ~
Thanx nimesh and MayJune.

Quote:
Originally Posted by shabbir View Post
I knew about this but I changed and framed the question a bit different hoping Saswat would not know it
Why are people targeting me ? LOL !?!
mayjune's Avatar, Join Date: Jun 2009
Invasive contributor
They say, when everyone is criticizing you (targeting you) you are on the right track
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Quote:
Originally Posted by mayjune View Post
They say, when everyone is criticizing you (targeting you) you are on the right track
And Famous